Using "<=" instead "<" to compare inline data size.

Fixes: bdaf1327 ("nvmet-tcp: fix a segmentation fault during io parsing error")
Signed-off-by: Hou Pu <houpu.main@gmail.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

We need to select NVME_CORE.
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Add an additional decoding for 'host pathing error' during connect.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Returning an nvme status from nvme_fc_create_association() indicates
that the association is established, and we should honour the DNR bit.
If it's set a reconnect attempt will just return the same error, so
we can short-circuit the reconnect attempts and fail the connection
directly.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Reviewed-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

We need to call put_device if cdev_device_add failed, otherwise
kmemleak has below report.

[<0000000024c71758>] kmem_cache_alloc_trace+0x233/0x480
[<00000000ad2813ed>] device_add+0x7ff/0xe10
[<0000000035bc54c4>] cdev_device_add+0x72/0xa0
[<000000006c9aa1e8>] nvme_cdev_add+0xa9/0xf0 [nvme_core]
[<000000003c4d492d>] nvme_mpath_set_live+0x251/0x290 [nvme_core]
[<00000000889a58da>] nvme_mpath_add_disk+0x268/0x320 [nvme_core]
[<00000000192e7161>] nvme_alloc_ns+0x669/0xac0 [nvme_core]
[<000000007a1a6041>] nvme_validate_or_alloc_ns+0x156/0x280 [nvme_core]
[<000000003a763c35>] nvme_scan_work+0x221/0x3c0 [nvme_core]
[<000000009ff10706>] process_one_work+0x5cf/0xb10
[<000000000644ee25>] worker_thread+0x7a/0x680
[<00000000285ebd2f>] kthread+0x1c6/0x210
[<00000000e297c6ea>] ret_from_fork+0x22/0x30

Fixes: 2637baed ("nvme: introduce generic per-namespace chardev")
Signed-off-by: Guoqing Jiang <jiangguoqing@kylinos.cn>
Reviewed-by: Javier González <javier.gonz@samsung.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

When BLKRRPART is called concurrently with del_gendisk, the partitions
rescan can create a stale partition that will never be be cleaned up.

Fix this by checking the the disk is up before rescanning partitions
while under bd_mutex.
Signed-off-by: Gulam Mohamed <gulam.mohamed@oracle.com>
[hch: split from a larger patch]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20210514131842.1600568-3-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

As an artifact of how gendisk lookup used to work in earlier kernels,
GENHD_FL_UP is only cleared very late in del_gendisk, and a global lock
is used to prevent opens from succeeding while del_gendisk is tearing
down the gendisk.  Switch to clearing the flag early and under bd_mutex
so that callers can use bd_mutex to stabilize the flag, which removes
the need for the global mutex.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20210514131842.1600568-2-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pull NVMe fixes from Christoph:

"nvme fixes for Linux 5.13:

 - nvme-tcp corruption and timeout fixes (Sagi Grimberg, Keith Busch)
 - nvme-fc teardown fix (James Smart)
 - nvmet/nvme-loop memory leak fixes (Wu Bo)"

* tag 'nvme-5.13-2021-05-20' of git://git.infradead.org/nvme:
  nvme-fc: clear q_live at beginning of association teardown
  nvme-tcp: rerun io_work if req_list is not empty
  nvme-tcp: fix possible use-after-completion
  nvme-loop: fix memory leak in nvme_loop_create_ctrl()
  nvmet: fix memory leak in nvmet_alloc_ctrl()

The __nvmf_check_ready() routine used to bounce all filesystem io if the
controller state isn't LIVE.  However, a later patch changed the logic so
that it rejection ends up being based on the Q live check.  The FC
transport has a slightly different sequence from rdma and tcp for
shutting down queues/marking them non-live.  FC marks its queue non-live
after aborting all ios and waiting for their termination, leaving a
rather large window for filesystem io to continue to hit the transport.
Unfortunately this resulted in filesystem I/O or applications seeing I/O
errors.

Change the FC transport to mark the queues non-live at the first sign of
teardown for the association (when I/O is initially terminated).

Fixes: 73a53799 ("nvme-fabrics: allow to queue requests for live queues")
Signed-off-by: James Smart <jsmart2021@gmail.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

A possible race condition exists where the request to send data is
enqueued from nvme_tcp_handle_r2t()'s will not be observed by
nvme_tcp_send_all() if it happens to be running. The driver relies on
io_work to send the enqueued request when it is runs again, but the
concurrently running nvme_tcp_send_all() may not have released the
send_mutex at that time. If no future commands are enqueued to re-kick
the io_work, the request will timeout in the SEND_H2C state, resulting
in a timeout error like:

  nvme nvme0: queue 1: timeout request 0x3 type 6

Ensure the io_work continues to run as long as the req_list is not empty.

Fixes: db5ad6b7 ("nvme-tcp: try to send request in queue_rq context")
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Commit db5ad6b7 ("nvme-tcp: try to send request in queue_rq
context") added a second context that may perform a network send.
This means that now RX and TX are not serialized in nvme_tcp_io_work
and can run concurrently.

While there is correct mutual exclusion in the TX path (where
the send_mutex protect the queue socket send activity) RX activity,
and more specifically request completion may run concurrently.

This means we must guarantee that any mutation of the request state
related to its lifetime, bytes sent must not be accessed when a completion
may have possibly arrived back (and processed).

The race may trigger when a request completion arrives, processed
_and_ reused as a fresh new request, exactly in the (relatively short)
window between the last data payload sent and before the request iov_iter
is advanced.

Consider the following race:
1. 16K write request is queued
2. The nvme command and the data is sent to the controller (in-capsule
   or solicited by r2t)
3. After the last payload is sent but before the req.iter is advanced,
   the controller sends back a completion.
4. The completion is processed, the request is completed, and reused
   to transfer a new request (write or read)
5. The new request is queued, and the driver reset the request parameters
   (nvme_tcp_setup_cmd_pdu).
6. Now context in (2) resumes execution and advances the req.iter

==> use-after-completion as this is already a new request.

Fix this by making sure the request is not advanced after the last
data payload send, knowing that a completion may have arrived already.

An alternative solution would have been to delay the request completion
or state change waiting for reference counting on the TX path, but besides
adding atomic operations to the hot-path, it may present challenges in
multi-stage R2T scenarios where a r2t handler needs to be deferred to
an async execution.
Reported-by: Narayan Ayalasomayajula <narayan.ayalasomayajula@wdc.com>
Tested-by: Anil Mishra <anil.mishra@wdc.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Cc: stable@vger.kernel.org # v5.8+
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

When creating loop ctrl in nvme_loop_create_ctrl(), if nvme_init_ctrl()
fails, the loop ctrl should be freed before jumping to the "out" label.

Fixes: 3a85a5de ("nvme-loop: add a NVMe loopback host driver")
Signed-off-by: Wu Bo <wubo40@huawei.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

When creating ctrl in nvmet_alloc_ctrl(), if the cntlid_min is larger
than cntlid_max of the subsystem, and jumps to the
"out_free_changed_ns_list" label, but the ctrl->sqs lack of be freed.
Fix this by jumping to the "out_free_sqs" label.

Fixes: 94a39d61 ("nvmet: make ctrl-id configurable")
Signed-off-by: Wu Bo <wubo40@huawei.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Fix the following kernel-doc warning:

block/partitions/efi.c:685: warning: wrong kernel-doc identifier on line:
 * efi_partition(struct parsed_partitions *state)

Cc: Alexander Viro <viro@math.psu.edu>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20210513171708.8391-1-bvanassche@acm.orgSigned-off-by: Jens Axboe <axboe@kernel.dk>

If a tag set is shared across request queues (e.g. SCSI LUNs) then the
block layer core keeps track of the number of active request queues in
tags->active_queues. blk_mq_tag_busy() and blk_mq_tag_idle() update that
atomic counter if the hctx flag BLK_MQ_F_TAG_QUEUE_SHARED is set. Make
sure that blk_mq_exit_queue() calls blk_mq_tag_idle() before that flag is
cleared by blk_mq_del_queue_tag_set().

Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Fixes: 0d2602ca ("blk-mq: improve support for shared tags maps")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20210513171529.7977-1-bvanassche@acm.orgSigned-off-by: Jens Axboe <axboe@kernel.dk>

In case of shared sbitmap, request won't be held in plug list any more
sine commit 32bc15af ("blk-mq: Facilitate a shared sbitmap per
tagset"), this way makes request merge from flush plug list & batching
submission not possible, so cause performance regression.

Yanhui reports performance regression when running sequential IO
test(libaio, 16 jobs, 8 depth for each job) in VM, and the VM disk
is emulated with image stored on xfs/megaraid_sas.

Fix the issue by recovering original behavior to allow to hold request
in plug list.

Cc: Yanhui Ma <yama@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: kashyap.desai@broadcom.com
Fixes: 32bc15af ("blk-mq: Facilitate a shared sbitmap per tagset")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20210514022052.1047665-1-ming.lei@redhat.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pull NVMe fixes from Christoph:

"nvme fix for Linux 5.13

 - correct the check for using the inline bio in nvmet
   (Chaitanya Kulkarni)
 - demote unsupported command warnings (Chaitanya Kulkarni)
 - fix corruption due to double initializing ANA state (me, Hou Pu)
 - reset ns->file when open fails (Daniel Wagner)
 - fix a NULL deref when SEND is completed with error in nvmet-rdma
   (Michal Kalderon)"

* tag 'nvme-5.13-2021-05-13' of git://git.infradead.org/nvme:
  nvmet: use new ana_log_size instead the old one
  nvmet: seset ns->file when open fails
  nvmet: demote fabrics cmd parse err msg to debug
  nvmet: use helper to remove the duplicate code
  nvmet: demote discovery cmd parse err msg to debug
  nvmet-rdma: Fix NULL deref when SEND is completed with error
  nvmet: fix inline bio check for passthru
  nvmet: fix inline bio check for bdev-ns
  nvme-multipath: fix double initialization of ANA state

The new ana_log_size should be used instead of the old one.
Or kernel NULL pointer dereference will happen like below:

[   38.957849][   T69] BUG: kernel NULL pointer dereference, address: 000000000000003c
[   38.975550][   T69] #PF: supervisor write access in kernel mode
[   38.975955][   T69] #PF: error_code(0x0002) - not-present page
[   38.976905][   T69] PGD 0 P4D 0
[   38.979388][   T69] Oops: 0002 [#1] SMP NOPTI
[   38.980488][   T69] CPU: 0 PID: 69 Comm: kworker/0:2 Not tainted 5.12.0+ #54
[   38.981254][   T69] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[   38.982502][   T69] Workqueue: events nvme_loop_execute_work
[   38.985219][   T69] RIP: 0010:memcpy_orig+0x68/0x10f
[   38.986203][   T69] Code: 83 c2 20 eb 44 48 01 d6 48 01 d7 48 83 ea 20 0f 1f 00 48 83 ea 20 4c 8b 46 f8 4c 8b 4e f0 4c 8b 56 e8 4c 8b 5e e0 48 8d 76 e0 <4c> 89 47 f8 4c 89 4f f0 4c 89 57 e8 4c 89 5f e0 48 8d 7f e0 73 d2
[   38.987677][   T69] RSP: 0018:ffffc900001b7d48 EFLAGS: 00000287
[   38.987996][   T69] RAX: 0000000000000020 RBX: 0000000000000024 RCX: 0000000000000010
[   38.988327][   T69] RDX: ffffffffffffffe4 RSI: ffff8881084bc004 RDI: 0000000000000044
[   38.988620][   T69] RBP: 0000000000000024 R08: 0000000100000000 R09: 0000000000000000
[   38.988991][   T69] R10: 0000000100000000 R11: 0000000000000001 R12: 0000000000000024
[   38.989289][   T69] R13: ffff8881084bc000 R14: 0000000000000000 R15: 0000000000000024
[   38.989845][   T69] FS:  0000000000000000(0000) GS:ffff888237c00000(0000) knlGS:0000000000000000
[   38.990234][   T69] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   38.990490][   T69] CR2: 000000000000003c CR3: 00000001085b2000 CR4: 00000000000006f0
[   38.991105][   T69] Call Trace:
[   38.994157][   T69]  sg_copy_buffer+0xb8/0xf0
[   38.995357][   T69]  nvmet_copy_to_sgl+0x48/0x6d
[   38.995565][   T69]  nvmet_execute_get_log_page_ana+0xd4/0x1cb
[   38.995792][   T69]  nvmet_execute_get_log_page+0xc9/0x146
[   38.995992][   T69]  nvme_loop_execute_work+0x3e/0x44
[   38.996181][   T69]  process_one_work+0x1c3/0x3c0
[   38.996393][   T69]  worker_thread+0x44/0x3d0
[   38.996600][   T69]  ? cancel_delayed_work+0x90/0x90
[   38.996804][   T69]  kthread+0xf7/0x130
[   38.996961][   T69]  ? kthread_create_worker_on_cpu+0x70/0x70
[   38.997171][   T69]  ret_from_fork+0x22/0x30
[   38.997705][   T69] Modules linked in:
[   38.998741][   T69] CR2: 000000000000003c
[   39.000104][   T69] ---[ end trace e719927b609d0fa0 ]---

Fixes: 5e1f6899 ("nvme-multipath: fix double initialization of ANA state")
Signed-off-by: Hou Pu <houpu.main@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Reset the ns->file value to NULL also in the error case in
nvmet_file_ns_enable().

The ns->file variable points either to file object or contains the
error code after the filp_open() call. This can lead to following
problem:

When the user first setups an invalid file backend and tries to enable
the ns, it will fail. Then the user switches over to a bdev backend
and enables successfully the ns. The first received I/O will crash the
system because the IO backend is chosen based on the ns->file value:

static u16 nvmet_parse_io_cmd(struct nvmet_req *req)
{
	[...]

	if (req->ns->file)
		return nvmet_file_parse_io_cmd(req);

	return nvmet_bdev_parse_io_cmd(req);
}
Reported-by: Enzo Matsumiya <ematsumiya@suse.com>
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Replace the following two statements by the statement “goto put_nbd;”

	nbd_put(nbd);
	return 0;
Signed-off-by: Sun Ke <sunke32@huawei.com>
Suggested-by: Markus Elfring <Markus.Elfring@web.de>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20210512114331.1233964-3-sunke32@huawei.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Open /dev/nbdX first, the config_refs will be 1 and
the pointers in nbd_device are still null. Disconnect
/dev/nbdX, then reference a null recv_workq. The
protection by config_refs in nbd_genl_disconnect is useless.

[  656.366194] BUG: kernel NULL pointer dereference, address: 0000000000000020
[  656.368943] #PF: supervisor write access in kernel mode
[  656.369844] #PF: error_code(0x0002) - not-present page
[  656.370717] PGD 10cc87067 P4D 10cc87067 PUD 1074b4067 PMD 0
[  656.371693] Oops: 0002 [#1] SMP
[  656.372242] CPU: 5 PID: 7977 Comm: nbd-client Not tainted 5.11.0-rc5-00040-g76c057c8 #1
[  656.373661] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014
[  656.375904] RIP: 0010:mutex_lock+0x29/0x60
[  656.376627] Code: 00 0f 1f 44 00 00 55 48 89 fd 48 83 05 6f d7 fe 08 01 e8 7a c3 ff ff 48 83 05 6a d7 fe 08 01 31 c0 65 48 8b 14 25 00 6d 01 00 <f0> 48 0f b1 55 d
[  656.378934] RSP: 0018:ffffc900005eb9b0 EFLAGS: 00010246
[  656.379350] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[  656.379915] RDX: ffff888104cf2600 RSI: ffffffffaae8f452 RDI: 0000000000000020
[  656.380473] RBP: 0000000000000020 R08: 0000000000000000 R09: ffff88813bd6b318
[  656.381039] R10: 00000000000000c7 R11: fefefefefefefeff R12: ffff888102710b40
[  656.381599] R13: ffffc900005eb9e0 R14: ffffffffb2930680 R15: ffff88810770ef00
[  656.382166] FS:  00007fdf117ebb40(0000) GS:ffff88813bd40000(0000) knlGS:0000000000000000
[  656.382806] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  656.383261] CR2: 0000000000000020 CR3: 0000000100c84000 CR4: 00000000000006e0
[  656.383819] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  656.384370] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  656.384927] Call Trace:
[  656.385111]  flush_workqueue+0x92/0x6c0
[  656.385395]  nbd_disconnect_and_put+0x81/0xd0
[  656.385716]  nbd_genl_disconnect+0x125/0x2a0
[  656.386034]  genl_family_rcv_msg_doit.isra.0+0x102/0x1b0
[  656.386422]  genl_rcv_msg+0xfc/0x2b0
[  656.386685]  ? nbd_ioctl+0x490/0x490
[  656.386954]  ? genl_family_rcv_msg_doit.isra.0+0x1b0/0x1b0
[  656.387354]  netlink_rcv_skb+0x62/0x180
[  656.387638]  genl_rcv+0x34/0x60
[  656.387874]  netlink_unicast+0x26d/0x590
[  656.388162]  netlink_sendmsg+0x398/0x6c0
[  656.388451]  ? netlink_rcv_skb+0x180/0x180
[  656.388750]  ____sys_sendmsg+0x1da/0x320
[  656.389038]  ? ____sys_recvmsg+0x130/0x220
[  656.389334]  ___sys_sendmsg+0x8e/0xf0
[  656.389605]  ? ___sys_recvmsg+0xa2/0xf0
[  656.389889]  ? handle_mm_fault+0x1671/0x21d0
[  656.390201]  __sys_sendmsg+0x6d/0xe0
[  656.390464]  __x64_sys_sendmsg+0x23/0x30
[  656.390751]  do_syscall_64+0x45/0x70
[  656.391017]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

To fix it, just add if (nbd->recv_workq) to nbd_disconnect_and_put().

Fixes: e9e006f5 ("nbd: fix max number of supported devs")
Signed-off-by: Sun Ke <sunke32@huawei.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20210512114331.1233964-2-sunke32@huawei.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Last users of blk_account_rq gone with patch commit a1ce35fa
("block: remove dead elevator code") and now it gets no caller, it can
be safely removed.
Signed-off-by: Lin Feng <linf@wangsu.com>
Link: https://lore.kernel.org/r/20210512100124.173769-1-linf@wangsu.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

BFQ may merge a new bfq_queue, stably, with the last bfq_queue
created. In particular, BFQ first waits a little bit for some I/O to
flow inside the new queue, say Q2, if this is needed to understand
whether it is better or worse to merge Q2 with the last queue created,
say Q1. This delayed stable merge is performed by assigning
bic->stable_merge_bfqq = Q1, for the bic associated with Q1.

Yet, while waiting for some I/O to flow in Q2, a non-stable queue
merge of Q2 with Q1 may happen, causing the bic previously associated
with Q2 to be associated with exactly Q1 (bic->bfqq = Q1). After that,
Q2 and Q1 may happen to be split, and, in the split, Q1 may happen to
be recycled as a non-shared bfq_queue. In that case, Q1 may then
happen to undergo a stable merge with the bfq_queue pointed by
bic->stable_merge_bfqq. Yet bic->stable_merge_bfqq still points to
Q1. So Q1 would be merged with itself.

This commit fixes this error by intercepting this situation, and
canceling the schedule of the stable merge.

Fixes: 430a67f9 ("block, bfq: merge bursts of newly-created queues")
Signed-off-by: Pietro Pedroni <pedroni.pietro.96@gmail.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Link: https://lore.kernel.org/r/20210512094352.85545-2-paolo.valente@linaro.orgSigned-off-by: Jens Axboe <axboe@kernel.dk>

When the weight of an active iocg is updated, weight_updated() is called
which in turn calls __propagate_weights() to update the active and inuse
weights so that the effective hierarchical weights are update accordingly.

The current implementation is incorrect for inner active nodes. For an
active leaf iocg, inuse can be any value between 1 and active and the
difference represents how much the iocg is donating. When weight is updated,
as long as inuse is clamped between 1 and the new weight, we're alright and
this is what __propagate_weights() currently implements.

However, that's not how an active inner node's inuse is set. An inner node's
inuse is solely determined by the ratio between the sums of inuse's and
active's of its children - ie. they're results of propagating the leaves'
active and inuse weights upwards. __propagate_weights() incorrectly applies
the same clamping as for a leaf when an active inner node's weight is
updated. Consider a hierarchy which looks like the following with saturating
workloads in AA and BB.

     R
   /   \
  A     B
  |     |
 AA     BB

1. For both A and B, active=100, inuse=100, hwa=0.5, hwi=0.5.

2. echo 200 > A/io.weight

3. __propagate_weights() update A's active to 200 and leave inuse at 100 as
   it's already between 1 and the new active, making A:active=200,
   A:inuse=100. As R's active_sum is updated along with A's active,
   A:hwa=2/3, B:hwa=1/3. However, because the inuses didn't change, the
   hwi's remain unchanged at 0.5.

4. The weight of A is now twice that of B but AA and BB still have the same
   hwi of 0.5 and thus are doing the same amount of IOs.

Fix it by making __propgate_weights() always calculate the inuse of an
active inner iocg based on the ratio of child_inuse_sum to child_active_sum.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Dan Schatzberg <dschatzberg@fb.com>
Fixes: 7caa4715 ("blkcg: implement blk-iocost")
Cc: stable@vger.kernel.org # v5.4+
Link: https://lore.kernel.org/r/YJsxnLZV1MnBcqjj@slm.duckdns.orgSigned-off-by: Jens Axboe <axboe@kernel.dk>

Host can send invalid commands and flood the target with error messages.
Demote the error message from pr_err() to pr_debug() in
nvmet_parse_fabrics_cmd() and nvmet_parse_connect_cmd().
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Use the helper nvmet_report_invalid_opcode() to report invalid opcode
so we can remove the duplicate code.
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Host can send invalid commands and flood the target with error messages
for the discovery controller. Demote the error message from pr_err() to
pr_debug( in nvmet_parse_discovery_cmd(). 
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

When running some traffic and taking down the link on peer, a
retry counter exceeded error is received. This leads to
nvmet_rdma_error_comp which tried accessing the cq_context to
obtain the queue. The cq_context is no longer valid after the
fix to use shared CQ mechanism and should be obtained similar
to how it is obtained in other functions from the wc->qp.

[ 905.786331] nvmet_rdma: SEND for CQE 0x00000000e3337f90 failed with status transport retry counter exceeded (12).
[ 905.832048] BUG: unable to handle kernel NULL pointer dereference at 0000000000000048
[ 905.839919] PGD 0 P4D 0
[ 905.842464] Oops: 0000 1 SMP NOPTI
[ 905.846144] CPU: 13 PID: 1557 Comm: kworker/13:1H Kdump: loaded Tainted: G OE --------- - - 4.18.0-304.el8.x86_64 #1
[ 905.872135] RIP: 0010:nvmet_rdma_error_comp+0x5/0x1b [nvmet_rdma]
[ 905.878259] Code: 19 4f c0 e8 89 b3 a5 f6 e9 5b e0 ff ff 0f b7 75 14 4c 89 ea 48 c7 c7 08 1a 4f c0 e8 71 b3 a5 f6 e9 4b e0 ff ff 0f 1f 44 00 00 <48> 8b 47 48 48 85 c0 74 08 48 89 c7 e9 98 bf 49 00 e9 c3 e3 ff ff
[ 905.897135] RSP: 0018:ffffab601c45fe28 EFLAGS: 00010246
[ 905.902387] RAX: 0000000000000065 RBX: ffff9e729ea2f800 RCX: 0000000000000000
[ 905.909558] RDX: 0000000000000000 RSI: ffff9e72df9567c8 RDI: 0000000000000000
[ 905.916731] RBP: ffff9e729ea2b400 R08: 000000000000074d R09: 0000000000000074
[ 905.923903] R10: 0000000000000000 R11: ffffab601c45fcc0 R12: 0000000000000010
[ 905.931074] R13: 0000000000000000 R14: 0000000000000010 R15: ffff9e729ea2f400
[ 905.938247] FS: 0000000000000000(0000) GS:ffff9e72df940000(0000) knlGS:0000000000000000
[ 905.938249] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 905.950067] nvmet_rdma: SEND for CQE 0x00000000c7356cca failed with status transport retry counter exceeded (12).
[ 905.961855] CR2: 0000000000000048 CR3: 000000678d010004 CR4: 00000000007706e0
[ 905.961855] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 905.961856] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 905.961857] PKRU: 55555554
[ 906.010315] Call Trace:
[ 906.012778] __ib_process_cq+0x89/0x170 [ib_core]
[ 906.017509] ib_cq_poll_work+0x26/0x80 [ib_core]
[ 906.022152] process_one_work+0x1a7/0x360
[ 906.026182] ? create_worker+0x1a0/0x1a0
[ 906.030123] worker_thread+0x30/0x390
[ 906.033802] ? create_worker+0x1a0/0x1a0
[ 906.037744] kthread+0x116/0x130
[ 906.040988] ? kthread_flush_work_fn+0x10/0x10
[ 906.045456] ret_from_fork+0x1f/0x40

Fixes: ca0f1a80 ("nvmet-rdma: use new shared CQ mechanism")
Signed-off-by: Shai Malin <smalin@marvell.com>
Signed-off-by: Michal Kalderon <michal.kalderon@marvell.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

When handling passthru commands, for inline bio allocation we only
consider the transfer size. This works well when req->sg_cnt fits into
the req->inline_bvec, but it will result in the early return from
bio_add_hw_page() when req->sg_cnt > NVMET_MAX_INLINE_BVEC.

Consider an I/O of size 32768 and first buffer is not aligned to the
page boundary, then I/O is split in following manner :-

[ 2206.256140] nvmet: sg->length 3440 sg->offset 656
[ 2206.256144] nvmet: sg->length 4096 sg->offset 0
[ 2206.256148] nvmet: sg->length 4096 sg->offset 0
[ 2206.256152] nvmet: sg->length 4096 sg->offset 0
[ 2206.256155] nvmet: sg->length 4096 sg->offset 0
[ 2206.256159] nvmet: sg->length 4096 sg->offset 0
[ 2206.256163] nvmet: sg->length 4096 sg->offset 0
[ 2206.256166] nvmet: sg->length 4096 sg->offset 0
[ 2206.256170] nvmet: sg->length 656 sg->offset 0

Now the req->transfer_size == NVMET_MAX_INLINE_DATA_LEN i.e. 32768, but
the req->sg_cnt is (9) > NVMET_MAX_INLINE_BIOVEC which is (8).
This will result in early return in the following code path :-

nvmet_bdev_execute_rw()
	bio_add_pc_page()
		bio_add_hw_page()
			if (bio_full(bio, len))
				return 0;

Use previously introduced helper nvmet_use_inline_bvec() to consider
req->sg_cnt when using inline bio. This only affects nvme-loop
transport.

Fixes: dab3902b ("nvmet: use inline bio for passthru fast path")
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

When handling rw commands, for inline bio case we only consider
transfer size. This works well when req->sg_cnt fits into the
req->inline_bvec, but it will result in the warning in
__bio_add_page() when req->sg_cnt > NVMET_MAX_INLINE_BVEC.

Consider an I/O size 32768 and first page is not aligned to the page
boundary, then I/O is split in following manner :-

[ 2206.256140] nvmet: sg->length 3440 sg->offset 656
[ 2206.256144] nvmet: sg->length 4096 sg->offset 0
[ 2206.256148] nvmet: sg->length 4096 sg->offset 0
[ 2206.256152] nvmet: sg->length 4096 sg->offset 0
[ 2206.256155] nvmet: sg->length 4096 sg->offset 0
[ 2206.256159] nvmet: sg->length 4096 sg->offset 0
[ 2206.256163] nvmet: sg->length 4096 sg->offset 0
[ 2206.256166] nvmet: sg->length 4096 sg->offset 0
[ 2206.256170] nvmet: sg->length 656 sg->offset 0

Now the req->transfer_size == NVMET_MAX_INLINE_DATA_LEN i.e. 32768, but
the req->sg_cnt is (9) > NVMET_MAX_INLINE_BIOVEC which is (8).
This will result in the following warning message :-

nvmet_bdev_execute_rw()
	bio_add_page()
		__bio_add_page()
			WARN_ON_ONCE(bio_full(bio, len));

This scenario is very hard to reproduce on the nvme-loop transport only
with rw commands issued with the passthru IOCTL interface from the host
application and the data buffer is allocated with the malloc() and not
the posix_memalign().

Fixes: 73383adf ("nvmet: don't split large I/Os unconditionally")
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvme_init_identify and thus nvme_mpath_init can be called multiple
times and thus must not overwrite potentially initialized or in-use
fields.  Split out a helper for the basic initialization when the
controller is initialized and make sure the init_identify path does
not blindly change in-use data structures.

Fixes: 0d0b660f ("nvme: add ANA support")
Reported-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Hannes Reinecke <hare@suse.de>

__blk_mq_sched_bio_merge() gets the ctx and hctx for the current CPU and
passes the hctx to ->bio_merge(). kyber_bio_merge() then gets the ctx
for the current CPU again and uses that to get the corresponding Kyber
context in the passed hctx. However, the thread may be preempted between
the two calls to blk_mq_get_ctx(), and the ctx returned the second time
may no longer correspond to the passed hctx. This "works" accidentally
most of the time, but it can cause us to read garbage if the second ctx
came from an hctx with more ctx's than the first one (i.e., if
ctx->index_hw[hctx->type] > hctx->nr_ctx).

This manifested as this UBSAN array index out of bounds error reported
by Jakub:

UBSAN: array-index-out-of-bounds in ../kernel/locking/qspinlock.c:130:9
index 13106 is out of range for type 'long unsigned int [128]'
Call Trace:
 dump_stack+0xa4/0xe5
 ubsan_epilogue+0x5/0x40
 __ubsan_handle_out_of_bounds.cold.13+0x2a/0x34
 queued_spin_lock_slowpath+0x476/0x480
 do_raw_spin_lock+0x1c2/0x1d0
 kyber_bio_merge+0x112/0x180
 blk_mq_submit_bio+0x1f5/0x1100
 submit_bio_noacct+0x7b0/0x870
 submit_bio+0xc2/0x3a0
 btrfs_map_bio+0x4f0/0x9d0
 btrfs_submit_data_bio+0x24e/0x310
 submit_one_bio+0x7f/0xb0
 submit_extent_page+0xc4/0x440
 __extent_writepage_io+0x2b8/0x5e0
 __extent_writepage+0x28d/0x6e0
 extent_write_cache_pages+0x4d7/0x7a0
 extent_writepages+0xa2/0x110
 do_writepages+0x8f/0x180
 __writeback_single_inode+0x99/0x7f0
 writeback_sb_inodes+0x34e/0x790
 __writeback_inodes_wb+0x9e/0x120
 wb_writeback+0x4d2/0x660
 wb_workfn+0x64d/0xa10
 process_one_work+0x53a/0xa80
 worker_thread+0x69/0x5b0
 kthread+0x20b/0x240
 ret_from_fork+0x1f/0x30

Only Kyber uses the hctx, so fix it by passing the request_queue to
->bio_merge() instead. BFQ and mq-deadline just use that, and Kyber can
map the queues itself to avoid the mismatch.

Fixes: a6088845 ("block: kyber: make kyber more friendly with merging")
Reported-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Link: https://lore.kernel.org/r/c7598605401a48d5cfeadebb678abd10af22b83f.1620691329.git.osandov@fb.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Fix the comment mentioning ioctl command range used for zoned block
devices to reflect the range of commands actually implemented.
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Link: https://lore.kernel.org/r/20210509234806.3000-1-damien.lemoal@wdc.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

This reverts commit cd2c7545.

Alex reports that the commit causes corruption with LUKS on ext4. Revert
it for now so that this can be investigated properly.

Link: https://lore.kernel.org/linux-block/1620493841.bxdq8r5haw.none@localhost/Reported-by: Alex Xu (Hello71) <alex_y_xu@yahoo.ca>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

We get a bug:

BUG: KASAN: slab-out-of-bounds in iov_iter_revert+0x11c/0x404
lib/iov_iter.c:1139
Read of size 8 at addr ffff0000d3fb11f8 by task

CPU: 0 PID: 12582 Comm: syz-executor.2 Not tainted
5.10.0-00843-g352c8610ccd2 #2
Hardware name: linux,dummy-virt (DT)
Call trace:
 dump_backtrace+0x0/0x2d0 arch/arm64/kernel/stacktrace.c:132
 show_stack+0x28/0x34 arch/arm64/kernel/stacktrace.c:196
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x110/0x164 lib/dump_stack.c:118
 print_address_description+0x78/0x5c8 mm/kasan/report.c:385
 __kasan_report mm/kasan/report.c:545 [inline]
 kasan_report+0x148/0x1e4 mm/kasan/report.c:562
 check_memory_region_inline mm/kasan/generic.c:183 [inline]
 __asan_load8+0xb4/0xbc mm/kasan/generic.c:252
 iov_iter_revert+0x11c/0x404 lib/iov_iter.c:1139
 io_read fs/io_uring.c:3421 [inline]
 io_issue_sqe+0x2344/0x2d64 fs/io_uring.c:5943
 __io_queue_sqe+0x19c/0x520 fs/io_uring.c:6260
 io_queue_sqe+0x2a4/0x590 fs/io_uring.c:6326
 io_submit_sqe fs/io_uring.c:6395 [inline]
 io_submit_sqes+0x4c0/0xa04 fs/io_uring.c:6624
 __do_sys_io_uring_enter fs/io_uring.c:9013 [inline]
 __se_sys_io_uring_enter fs/io_uring.c:8960 [inline]
 __arm64_sys_io_uring_enter+0x190/0x708 fs/io_uring.c:8960
 __invoke_syscall arch/arm64/kernel/syscall.c:36 [inline]
 invoke_syscall arch/arm64/kernel/syscall.c:48 [inline]
 el0_svc_common arch/arm64/kernel/syscall.c:158 [inline]
 do_el0_svc+0x120/0x290 arch/arm64/kernel/syscall.c:227
 el0_svc+0x1c/0x28 arch/arm64/kernel/entry-common.c:367
 el0_sync_handler+0x98/0x170 arch/arm64/kernel/entry-common.c:383
 el0_sync+0x140/0x180 arch/arm64/kernel/entry.S:670

Allocated by task 12570:
 stack_trace_save+0x80/0xb8 kernel/stacktrace.c:121
 kasan_save_stack mm/kasan/common.c:48 [inline]
 kasan_set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc+0xdc/0x120 mm/kasan/common.c:461
 kasan_kmalloc+0xc/0x14 mm/kasan/common.c:475
 __kmalloc+0x23c/0x334 mm/slub.c:3970
 kmalloc include/linux/slab.h:557 [inline]
 __io_alloc_async_data+0x68/0x9c fs/io_uring.c:3210
 io_setup_async_rw fs/io_uring.c:3229 [inline]
 io_read fs/io_uring.c:3436 [inline]
 io_issue_sqe+0x2954/0x2d64 fs/io_uring.c:5943
 __io_queue_sqe+0x19c/0x520 fs/io_uring.c:6260
 io_queue_sqe+0x2a4/0x590 fs/io_uring.c:6326
 io_submit_sqe fs/io_uring.c:6395 [inline]
 io_submit_sqes+0x4c0/0xa04 fs/io_uring.c:6624
 __do_sys_io_uring_enter fs/io_uring.c:9013 [inline]
 __se_sys_io_uring_enter fs/io_uring.c:8960 [inline]
 __arm64_sys_io_uring_enter+0x190/0x708 fs/io_uring.c:8960
 __invoke_syscall arch/arm64/kernel/syscall.c:36 [inline]
 invoke_syscall arch/arm64/kernel/syscall.c:48 [inline]
 el0_svc_common arch/arm64/kernel/syscall.c:158 [inline]
 do_el0_svc+0x120/0x290 arch/arm64/kernel/syscall.c:227
 el0_svc+0x1c/0x28 arch/arm64/kernel/entry-common.c:367
 el0_sync_handler+0x98/0x170 arch/arm64/kernel/entry-common.c:383
 el0_sync+0x140/0x180 arch/arm64/kernel/entry.S:670

Freed by task 12570:
 stack_trace_save+0x80/0xb8 kernel/stacktrace.c:121
 kasan_save_stack mm/kasan/common.c:48 [inline]
 kasan_set_track+0x38/0x6c mm/kasan/common.c:56
 kasan_set_free_info+0x20/0x40 mm/kasan/generic.c:355
 __kasan_slab_free+0x124/0x150 mm/kasan/common.c:422
 kasan_slab_free+0x10/0x1c mm/kasan/common.c:431
 slab_free_hook mm/slub.c:1544 [inline]
 slab_free_freelist_hook mm/slub.c:1577 [inline]
 slab_free mm/slub.c:3142 [inline]
 kfree+0x104/0x38c mm/slub.c:4124
 io_dismantle_req fs/io_uring.c:1855 [inline]
 __io_free_req+0x70/0x254 fs/io_uring.c:1867
 io_put_req_find_next fs/io_uring.c:2173 [inline]
 __io_queue_sqe+0x1fc/0x520 fs/io_uring.c:6279
 __io_req_task_submit+0x154/0x21c fs/io_uring.c:2051
 io_req_task_submit+0x2c/0x44 fs/io_uring.c:2063
 task_work_run+0xdc/0x128 kernel/task_work.c:151
 get_signal+0x6f8/0x980 kernel/signal.c:2562
 do_signal+0x108/0x3a4 arch/arm64/kernel/signal.c:658
 do_notify_resume+0xbc/0x25c arch/arm64/kernel/signal.c:722
 work_pending+0xc/0x180

blkdev_read_iter can truncate iov_iter's count since the count + pos may
exceed the size of the blkdev. This will confuse io_read that we have
consume the iovec. And once we do the iov_iter_revert in io_read, we
will trigger the slab-out-of-bounds. Fix it by reexpand the count with
size has been truncated.

blkdev_write_iter can trigger the problem too.
Signed-off-by: yangerkun <yangerkun@huawei.com>
Acked-by: Pavel Begunkov <asml.silencec@gmail.com>
Link: https://lore.kernel.org/r/20210401071807.3328235-1-yangerkun@huawei.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pull NVMe fixes from Christoph:

"nvme updates for Linux 5.13

 - reset the bdev to ns head when failover (Daniel Wagner)
 - remove unsupported command noise (Keith Busch)
 - misc passthrough improvements (Kanchan Joshi)
 - fix controller ioctl through ns_head (Minwoo Im)
 - fix controller timeouts during reset (Tao Chiu)"

* tag 'nvme-5.13-2021-05-05' of git://git.infradead.org/nvme:
  nvmet: remove unsupported command noise
  nvme-multipath: reset bdev to ns head when failover
  nvme-pci: fix controller reset hang when racing with nvme_timeout
  nvme: move the fabrics queue ready check routines to core
  nvme: avoid memset for passthrough requests
  nvme: add nvme_get_ns helper
  nvme: fix controller ioctl through ns_head

Nothing can stop a host from submitting invalid commands. The target
just needs to respond with an appropriate status, but that's not a
target error. Demote invalid command messages to the debug level so
these events don't spam the kernel logs.
Reported-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Klaus Jensen <k.jensen@samsung.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

When a request finally completes in end_io() after it has failed over,
the bdev pointer can be stale and thus the system can crash. Set the
bdev back to ns head, so the request is map to an active path when
resubmitted.
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

reset_work() in nvme-pci may hang forever in the following scenario:
1) A reset caused by a command timeout occurs due to a controller being
   temporarily irresponsive.
2) nvme_reset_work() restarts admin queue at nvme_alloc_admin_tags(). At
   the same time, a user-submitted admin command is queued and waiting
   for completion. Then, reset_work() changes its state to CONNECTING,
   and submits an identify command.
3) However, the controller does still not respond to any command,
   causing a timeout being fired at the user-submitted command.
   Unfortunately, nvme_timeout() does not see the completion on cq, and
   any timeout that takes place under CONNECTING state causes a
   controller shutdown.
4) Normally, the identify command in reset_work() would be canceled with
   SC_HOST_ABORTED by nvme_dev_disable(), then reset_work can tear down
   the controller accordingly. But the controller happens to return
   online and respond the identify command before nvme_dev_disable()
   should have been reaped it off.
5) reset_work() continues to setup_io_queues() as it observes no error
   in init_identify(). However, the admin queue has already been
   quiesced in dev_disable(). Thus, any following commands would be
   blocked forever in blk_execute_rq().

This can be fixed by restricting usercmd commands when controller is not
in a LIVE state in nvme_queue_rq(), as what has been done previously in
fabrics.

```
nvme_reset_work():                     |
    nvme_alloc_admin_tags()            |
                                       | nvme_submit_user_cmd():
    nvme_init_identify():              |     ...
        __nvme_submit_sync_cmd():      |
            ...                        |     ...
---------------------------------------> nvme_timeout():
(Controller starts reponding commands) |     nvme_dev_disable(, true):
    nvme_setup_io_queues():            |
        __nvme_submit_sync_cmd():      |
            (hung in blk_execute_rq    |
             since run_hw_queue sees   |
             queue quiesced)           |

```
Signed-off-by: Tao Chiu <taochiu@synology.com>
Signed-off-by: Cody Wong <codywong@synology.com>
Reviewed-by: Leon Chien <leonchien@synology.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>

queue_rq() in pci only checks if the dispatched queue (nvmeq) is ready,
e.g. not being suspended. Since nvme_alloc_admin_tags() in reset flow
restarts the admin queue, users are able to submit admin commands to a
controller before reset_work() completes. Commands submitted under this
condition may interfere with commands that performs identify, IO queue
setup in reset_work(), and may result in a hang described in the
following patch.

As seen in the fabrics, user commands are prevented from being executed
under inproper controller states. We may reuse this logic to maintain a
clear admin queue during reset_work().
Signed-off-by: Tao Chiu <taochiu@synology.com>
Signed-off-by: Cody Wong <codywong@synology.com>
Reviewed-by: Leon Chien <leonchien@synology.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>