The nvmf_check_if_ready() checks that were added are very simplistic.
As such, the routine allows a lot of cases to fail ios during windows
of reset or re-connection. In cases where there are not multi-path
options present, the error goes back to the callee - the filesystem
or application. Not good.

The common routine was rewritten and calling syntax slightly expanded
so that per-transport is_ready routines don't need to be present.
The transports now call the routine directly. The routine is now a
fabrics routine rather than an inline function.

The routine now looks at controller state to decide the action to
take. Some states mandate io failure. Others define the condition where
a command can be accepted.  When the decision is unclear, a generic
queue-or-reject check is made to look for failfast or multipath ios and
only fails the io if it is so marked. Otherwise, the io will be queued
and wait for the controller state to resolve.

Admin commands issued via ioctl share a live admin queue with commands
from the transport for controller init. The ioctls could be intermixed
with the initialization commands. It's possible for the ioctl cmd to
be issued prior to the controller being enabled. To block this, the
ioctl admin commands need to be distinguished from admin commands used
for controller init. Added a USERCMD nvme_req(req)->rq_flags bit to
reflect this division and set it on ioctls requests.  As the
nvmf_check_if_ready() routine is called prior to nvme_setup_cmd(),
ensure that commands allocated by the ioctl path (actually anything
in core.c) preps the nvme_req(req) before starting the io. This will
preserve the USERCMD flag during execution and/or retry.

Signed-off-by: James Smart <james.smart@broadcom.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.e>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Commit 42de82a8 previously attempted to fix this, and it did
correctly pad the MN and FR fields with spaces, but the SN field still
contains 0 bytes.  The current code fills out the first 16 bytes with
hex2bin, leaving the last 4 bytes zeroed.  Rather than adding a lot of
error-prone math to avoid overwriting SN twice, just set the whole thing
to spaces up front (it's only 20 bytes).

Fixes: 42de82a8 ("nvmet: don't report 0-bytes in serial number")
Signed-off-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Also add error flow in case srcu initialization function fails.

Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

We have to increment the number of logical blocks to a 1's based value
in the native format prior to converting to 512b units.

Signed-off-by: Rodrigo R. Galvao <rosattig@linux.vnet.ibm.com>
[changelog]
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

The admin and first IO queues shared the first irq vector, which has an
affinity mask including cpu0. If a system allows cpu0 to be offlined,
the admin queue may not be usable if no other CPUs in the affinity mask
are online. This is a problem since unlike IO queues, there is only
one admin queue that always needs to be usable.

To fix, this patch allocates one pre_vector for the admin queue that
is assigned all CPUs, so will always be accessible. The IO queues are
assigned the remaining managed vectors.

In case a controller has only one interrupt vector available, the admin
and IO queues will share the pre_vector with all CPUs assigned.

Cc: Jianchao Wang <jianchao.w.wang@oracle.com>
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

All the queue memory is allocated up front. We don't take the node
into consideration when creating queues anymore, so removing the unused
parameter.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

User reported controller always retains CSTS.RDY to 1, which fails
controller disabling when resetting the controller. This is also before
the admin queue is allocated, and trying to disable an unallocated queue
results in a NULL dereference.

Reported-by: Alex Gagniuc <Alex_Gagniuc@Dellteam.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

nvmet_execute_get_disc_log_page() passes a fixed-length string into
nvmet_format_discovery_entry(), which then does a longer memcpy() on
it, as pointed out by gcc-8:

In function 'nvmet_format_discovery_entry',
    inlined from 'nvmet_execute_get_disc_log_page' at drivers/nvme/target/discovery.c:126:4:
drivers/nvme/target/discovery.c:62:2: error: 'memcpy' forming offset [38, 223] is out of the bounds [0, 37] [-Werror=array-bounds]
  memcpy(e->subnqn, subsys_nqn, NVMF_NQN_SIZE);

Using strncpy() will make this well-defined, filling the rest of the
buffer with zeroes, under the assumption that the input is either
a NUL-terminated string, or a byte sequence containing no zeroes.
If the input is a string that is longer than NVMF_NQN_SIZE, we
continue to have no NUL-termination in the output.

Fixes: a07b4970 ("nvmet: add a generic NVMe target")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

NVMe over Fabrics 1.0 Section 5.2 "Discovery Controller Properties and
Command Support" Figure 31 "Discovery Controller – Admin Commands"
explicitly listst all commands but "Get Log Page" and "Identify" as
reserved, but NetApp report the Linux host is sending Keep Alive
commands to the discovery controller, which is a violation of the
Spec.

We're already checking for discovery controllers when configuring the
keep alive timeout but when creating a discovery controller we're not
hard wiring the keep alive timeout to 0 and thus remain on
NVME_DEFAULT_KATO for the discovery controller.

This can be easily remproduced when issuing a direct connect to the
discovery susbsystem using:
'nvme connect [...] --nqn=nqn.2014-08.org.nvmexpress.discovery'

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Fixes: 07bfcd09 ("nvme-fabrics: add a generic NVMe over Fabrics library")
Reported-by: Martin George <marting@netapp.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

nvme_start_keep_alive() isn't used outside core.c so unexport it and
make it static.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

When nvmet_req_init() fails, __nvmet_req_complete() is called
to handle the target request via .queue_response(), so
nvme_loop_queue_response() shouldn't be called again for
handling the failure.

This patch fixes this case by the following way:

- move blk_mq_start_request() before nvmet_req_init(), so
nvme_loop_queue_response() may work well to complete this
host request

- don't call nvme_cleanup_cmd() which is done in nvme_loop_complete_rq()

- don't call nvme_loop_queue_response() which is done via
.queue_response()

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
[trimmed changelog]
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Compiling on 32 bits system produces a warning for the shift width
when shifting 32 bit integer with 64bit integer.

Make sure that offset always is 64bit, and use macros for retrieving
lower and upper bits of the offset.

Signed-off-by: Matias Bjørling <mb@lightnvm.io>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

We can't just use scsi_cd() to get the scsi_cd structure, we have
to grab a live reference to the device. For both callbacks, we're
not inside an open where we already hold a reference to the device.

This fixes device removal/addition under concurrent device access,
which otherwise could result in the below oops.

NULL pointer dereference at 0000000000000010
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP
Modules linked in:
sr 12:0:0:0: [sr2] scsi-1 drive
 scsi_debug crc_t10dif crct10dif_generic crct10dif_common nvme nvme_core sb_edac xl
sr 12:0:0:0: Attached scsi CD-ROM sr2
 sr_mod cdrom btrfs xor zstd_decompress zstd_compress xxhash lzo_compress zlib_defc
sr 12:0:0:0: Attached scsi generic sg7 type 5
 igb ahci libahci i2c_algo_bit libata dca [last unloaded: crc_t10dif]
CPU: 43 PID: 4629 Comm: systemd-udevd Not tainted 4.16.0+ #650
Hardware name: Dell Inc. PowerEdge T630/0NT78X, BIOS 2.3.4 11/09/2016
RIP: 0010:sr_block_revalidate_disk+0x23/0x190 [sr_mod]
RSP: 0018:ffff883ff357bb58 EFLAGS: 00010292
RAX: ffffffffa00b07d0 RBX: ffff883ff3058000 RCX: ffff883ff357bb66
RDX: 0000000000000003 RSI: 0000000000007530 RDI: ffff881fea631000
RBP: 0000000000000000 R08: ffff881fe4d38400 R09: 0000000000000000
R10: 0000000000000000 R11: 00000000000001b6 R12: 000000000800005d
R13: 000000000800005d R14: ffff883ffd9b3790 R15: 0000000000000000
FS:  00007f7dc8e6d8c0(0000) GS:ffff883fff340000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000010 CR3: 0000003ffda98005 CR4: 00000000003606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 ? __invalidate_device+0x48/0x60
 check_disk_change+0x4c/0x60
 sr_block_open+0x16/0xd0 [sr_mod]
 __blkdev_get+0xb9/0x450
 ? iget5_locked+0x1c0/0x1e0
 blkdev_get+0x11e/0x320
 ? bdget+0x11d/0x150
 ? _raw_spin_unlock+0xa/0x20
 ? bd_acquire+0xc0/0xc0
 do_dentry_open+0x1b0/0x320
 ? inode_permission+0x24/0xc0
 path_openat+0x4e6/0x1420
 ? cpumask_any_but+0x1f/0x40
 ? flush_tlb_mm_range+0xa0/0x120
 do_filp_open+0x8c/0xf0
 ? __seccomp_filter+0x28/0x230
 ? _raw_spin_unlock+0xa/0x20
 ? __handle_mm_fault+0x7d6/0x9b0
 ? list_lru_add+0xa8/0xc0
 ? _raw_spin_unlock+0xa/0x20
 ? __alloc_fd+0xaf/0x160
 ? do_sys_open+0x1a6/0x230
 do_sys_open+0x1a6/0x230
 do_syscall_64+0x5a/0x100
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2

Reviewed-by: Lee Duncan <lduncan@suse.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

This reverts commit 127276c6.

When all CPUs of one hw queue become offline, there still may have IOs
not completed from this hctx. But blk_mq_hw_queue_mapped() is called in
blk_mq_queue_tag_busy_iter(), which is used for iterating request in timeout
handler, timeout event will be missed on the inactive hctx, then request may
never be completed.

Also the replementation of blk_mq_hw_queue_mapped() doesn't match the helper's
name any more, and it should have been named as blk_mq_hw_queue_active().

Even other callers need further verification about this reimplemenation.

So revert this patch now, and we can improve hw queue activate/inactivate event
after adequent researching and test.

Cc: Stefan Haberland <sth@linux.vnet.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Christoph Hellwig <hch@lst.de>
Reported-by: Jens Axboe <axboe@kernel.dk>
Fixes: 	127276c6 ("blk-mq: reimplement blk_mq_hw_queue_mapped")
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Because blkcg_exit_queue() is now called from inside blk_cleanup_queue()
it is no longer safe to access cgroup information during or after the
blk_cleanup_queue() call. Hence protect the generic_make_request_checks()
call with blk_queue_enter() / blk_queue_exit().

Reported-by: Ming Lei <ming.lei@redhat.com>
Fixes: a063057d ("block: Fix a race between request queue removal and the block cgroup controller")
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Joseph Qi <joseph.qi@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

__printf marker was added in commit d2cc4dde ("bdi_register: add
__printf verification, fix arg mismatch") for function `bdi_register`
since it is useful to verify format and arguments. Apply equivalent gcc
attribute to `bdi_register_va`.

Remove warning triggered with W=1:

  mm/backing-dev.c:881:2: warning: function might be possible candidate for ‘gnu_printf’ format attribute [-Wsuggest-attribute=format]

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Firstly, from commit 4b855ad3 ("blk-mq: Create hctx for each present CPU),
blk-mq doesn't remap queue any more after CPU topo is changed.

Secondly, set->nr_hw_queues can't be bigger than nr_cpu_ids, and now we map
all possible CPUs to hw queues, so at least one CPU is mapped to each hctx.

So queue mapping has became static and fixed just like percpu variable, and
we don't need to handle queue remapping any more.

Cc: Stefan Haberland <sth@linux.vnet.ibm.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Now the actual meaning of queue mapped is that if there is any online
CPU mapped to this hctx, so implement blk_mq_hw_queue_mapped() in this
way.

Cc: Stefan Haberland <sth@linux.vnet.ibm.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

There are several reasons for removing the check:

1) blk_mq_hw_queue_mapped() returns true always now since each hctx
may be mapped by one CPU at least

2) when there isn't any online CPU mapped to this hctx, there won't
be any IO queued to this CPU, blk_mq_run_hw_queue() only runs queue
if there is IO queued to this hctx

3) If __blk_mq_delay_run_hw_queue() is called by blk_mq_delay_run_hw_queue(),
which is run from blk_mq_dispatch_rq_list() or scsi_mq_get_budget(), and
the hctx to be handled has to be mapped.

Cc: Stefan Haberland <sth@linux.vnet.ibm.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

No driver uses this interface any more, so remove it.

Cc: Stefan Haberland <sth@linux.vnet.ibm.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

This patch introduces helper of blk_mq_hw_queue_first_cpu() for
figuring out the hctx's first cpu, and code duplication can be
avoided.

Cc: Stefan Haberland <sth@linux.vnet.ibm.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

This patch figures out the final selected CPU, then writes
it to hctx->next_cpu once, then we can avoid to intermediate
next cpu observed from other dispatch paths.

Cc: Stefan Haberland <sth@linux.vnet.ibm.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

From commit 4b855ad3 ("blk-mq: Create hctx for each present CPU),
blk-mq doesn't remap queue after CPU topo is changed, that said when
some of these offline CPUs become online, they are still mapped to
hctx 0, then hctx 0 may become the bottleneck of IO dispatch and
completion.

This patch sets up the mapping from the beginning, and aligns to
queue mapping for PCI device (blk_mq_pci_map_queues()).

Cc: Stefan Haberland <sth@linux.vnet.ibm.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: stable@vger.kernel.org
Fixes: 4b855ad3 ("blk-mq: Create hctx for each present CPU)
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

From commit 20e4d813 (blk-mq: simplify queue mapping & schedule
with each possisble CPU), one hctx can be mapped from all offline CPUs,
then hctx->next_cpu can be set as wrong.

This patch fixes this issue by making hctx->next_cpu pointing to the
first CPU in hctx->cpumask if all CPUs in hctx->cpumask are offline.

Cc: Stefan Haberland <sth@linux.vnet.ibm.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Fixes: 20e4d813 ("blk-mq: simplify queue mapping & schedule with each possisble CPU")
Cc: stable@vger.kernel.org
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Commit 2d1d4c1e made loop_get_status() drop lo_ctx_mutex before
returning, but the loop_get_status_old(), loop_get_status64(), and
loop_get_status_compat() wrappers don't call loop_get_status() if the
passed argument is NULL. The callers expect that the lock is dropped, so
make sure we drop it in that case, too.

Reported-by:  <syzbot+31e8daa8b3fc129e75f2@syzkaller.appspotmail.com>
Fixes: 2d1d4c1e ("loop: don't call into filesystem while holding lo_ctl_mutex")
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

syzbot is reporting deadlocks at __blkdev_get() [1].

----------------------------------------
[   92.493919] systemd-udevd   D12696   525      1 0x00000000
[   92.495891] Call Trace:
[   92.501560]  schedule+0x23/0x80
[   92.502923]  schedule_preempt_disabled+0x5/0x10
[   92.504645]  __mutex_lock+0x416/0x9e0
[   92.510760]  __blkdev_get+0x73/0x4f0
[   92.512220]  blkdev_get+0x12e/0x390
[   92.518151]  do_dentry_open+0x1c3/0x2f0
[   92.519815]  path_openat+0x5d9/0xdc0
[   92.521437]  do_filp_open+0x7d/0xf0
[   92.527365]  do_sys_open+0x1b8/0x250
[   92.528831]  do_syscall_64+0x6e/0x270
[   92.530341]  entry_SYSCALL_64_after_hwframe+0x42/0xb7

[   92.931922] 1 lock held by systemd-udevd/525:
[   92.933642]  #0: 00000000a2849e25 (&bdev->bd_mutex){+.+.}, at: __blkdev_get+0x73/0x4f0
----------------------------------------

The reason of deadlock turned out that wait_event_interruptible() in
blk_queue_enter() got stuck with bdev->bd_mutex held at __blkdev_put()
due to q->mq_freeze_depth == 1.

----------------------------------------
[   92.787172] a.out           S12584   634    633 0x80000002
[   92.789120] Call Trace:
[   92.796693]  schedule+0x23/0x80
[   92.797994]  blk_queue_enter+0x3cb/0x540
[   92.803272]  generic_make_request+0xf0/0x3d0
[   92.807970]  submit_bio+0x67/0x130
[   92.810928]  submit_bh_wbc+0x15e/0x190
[   92.812461]  __block_write_full_page+0x218/0x460
[   92.815792]  __writepage+0x11/0x50
[   92.817209]  write_cache_pages+0x1ae/0x3d0
[   92.825585]  generic_writepages+0x5a/0x90
[   92.831865]  do_writepages+0x43/0xd0
[   92.836972]  __filemap_fdatawrite_range+0xc1/0x100
[   92.838788]  filemap_write_and_wait+0x24/0x70
[   92.840491]  __blkdev_put+0x69/0x1e0
[   92.841949]  blkdev_close+0x16/0x20
[   92.843418]  __fput+0xda/0x1f0
[   92.844740]  task_work_run+0x87/0xb0
[   92.846215]  do_exit+0x2f5/0xba0
[   92.850528]  do_group_exit+0x34/0xb0
[   92.852018]  SyS_exit_group+0xb/0x10
[   92.853449]  do_syscall_64+0x6e/0x270
[   92.854944]  entry_SYSCALL_64_after_hwframe+0x42/0xb7

[   92.943530] 1 lock held by a.out/634:
[   92.945105]  #0: 00000000a2849e25 (&bdev->bd_mutex){+.+.}, at: __blkdev_put+0x3c/0x1e0
----------------------------------------

The reason of q->mq_freeze_depth == 1 turned out that loop_set_status()
forgot to call blk_mq_unfreeze_queue() at error paths for
info->lo_encrypt_type != NULL case.

----------------------------------------
[   37.509497] CPU: 2 PID: 634 Comm: a.out Tainted: G        W        4.16.0+ #457
[   37.513608] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/19/2017
[   37.518832] RIP: 0010:blk_freeze_queue_start+0x17/0x40
[   37.521778] RSP: 0018:ffffb0c2013e7c60 EFLAGS: 00010246
[   37.524078] RAX: 0000000000000000 RBX: ffff8b07b1519798 RCX: 0000000000000000
[   37.527015] RDX: 0000000000000002 RSI: ffffb0c2013e7cc0 RDI: ffff8b07b1519798
[   37.529934] RBP: ffffb0c2013e7cc0 R08: 0000000000000008 R09: 47a189966239b898
[   37.532684] R10: dad78b99b278552f R11: 9332dca72259d5ef R12: ffff8b07acd73678
[   37.535452] R13: 0000000000004c04 R14: 0000000000000000 R15: ffff8b07b841e940
[   37.538186] FS:  00007fede33b9740(0000) GS:ffff8b07b8e80000(0000) knlGS:0000000000000000
[   37.541168] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   37.543590] CR2: 00000000206fdf18 CR3: 0000000130b30006 CR4: 00000000000606e0
[   37.546410] Call Trace:
[   37.547902]  blk_freeze_queue+0x9/0x30
[   37.549968]  loop_set_status+0x67/0x3c0 [loop]
[   37.549975]  loop_set_status64+0x3b/0x70 [loop]
[   37.549986]  lo_ioctl+0x223/0x810 [loop]
[   37.549995]  blkdev_ioctl+0x572/0x980
[   37.550003]  block_ioctl+0x34/0x40
[   37.550006]  do_vfs_ioctl+0xa7/0x6d0
[   37.550017]  ksys_ioctl+0x6b/0x80
[   37.573076]  SyS_ioctl+0x5/0x10
[   37.574831]  do_syscall_64+0x6e/0x270
[   37.576769]  entry_SYSCALL_64_after_hwframe+0x42/0xb7
----------------------------------------

[1] https://syzkaller.appspot.com/bug?id=cd662bc3f6022c0979d01a262c318fab2ee9b56f



Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: syzbot <bot+48594378e9851eab70bcd6f99327c7db58c5a28a@syzkaller.appspotmail.com>
Fixes: ecdd0959 ("block/loop: fix race between I/O and set_status")
Cc: Ming Lei <tom.leiming@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: stable <stable@vger.kernel.org>
Cc: Jens Axboe <axboe@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

This patch orders getting budget and driver tag by making sure to acquire
driver tag after budget is got, this way can help to avoid the following
race:

1) before dispatch request from scheduler queue, get one budget first, then
dequeue a request, call it request A.

2) in another IO path for dispatching request B which is from hctx->dispatch,
driver tag is got, then try to get budget in blk_mq_dispatch_rq_list(),
unfortunately the budget is held by request A.

3) meantime blk_mq_dispatch_rq_list() is called for dispatching request
A, and try to get driver tag first, unfortunately no driver tag is
available because the driver tag is held by request B

4) both two IO pathes can't move on, and IO stall is caused.

This issue can be observed when running dbench on USB storage.

This patch fixes this issue by always getting budget before getting
driver tag.

Cc: stable@vger.kernel.org
Fixes: de148297 ("blk-mq: introduce .get_budget and .put_budget in blk_mq_ops")
Cc: Christoph Hellwig <hch@lst.de>
Cc: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Omar Sandoval <osandov@fb.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Pull SCSI updates from James Bottomley:
 "This is mostly updates of the usual drivers: arcmsr, qla2xx, lpfc,
  ufs, mpt3sas, hisi_sas.

  In addition we have removed several really old drivers: sym53c416,
  NCR53c406a, fdomain, fdomain_cs and removed the old scsi_module.c
  initialization from all remaining drivers.

  Plus an assortment of bug fixes, initialization errors and other minor
  fixes"

* tag 'scsi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (168 commits)
  scsi: ufs: Add support for Auto-Hibernate Idle Timer
  scsi: ufs: sysfs: reworking of the rpm_lvl and spm_lvl entries
  scsi: qla2xxx: fx00 copypaste typo
  scsi: qla2xxx: fix error message on <qla2400
  scsi: smartpqi: update driver version
  scsi: smartpqi: workaround fw bug for oq deletion
  scsi: arcmsr: Change driver version to v1.40.00.05-20180309
  scsi: arcmsr: Sleep to avoid CPU stuck too long for waiting adapter ready
  scsi: arcmsr: Handle adapter removed due to thunderbolt cable disconnection.
  scsi: arcmsr: Rename ACB_F_BUS_HANG_ON to ACB_F_ADAPTER_REMOVED for adapter hot-plug
  scsi: qla2xxx: Update driver version to 10.00.00.06-k
  scsi: qla2xxx: Fix Async GPN_FT for FCP and FC-NVMe scan
  scsi: qla2xxx: Cleanup code to improve FC-NVMe error handling
  scsi: qla2xxx: Fix FC-NVMe IO abort during driver reset
  scsi: qla2xxx: Fix retry for PRLI RJT with reason of BUSY
  scsi: qla2xxx: Remove nvme_done_list
  scsi: qla2xxx: Return busy if rport going away
  scsi: qla2xxx: Fix n2n_ae flag to prevent dev_loss on PDB change
  scsi: qla2xxx: Add FC-NVMe abort processing
  scsi: qla2xxx: Add changes for devloss timeout in driver
  ...

Pull block layer updates from Jens Axboe:
 "It's a pretty quiet round this time, which is nice. This contains:

   - series from Bart, cleaning up the way we set/test/clear atomic
     queue flags.

   - series from Bart, fixing races between gendisk and queue
     registration and removal.

   - set of bcache fixes and improvements from various folks, by way of
     Michael Lyle.

   - set of lightnvm updates from Matias, most of it being the 1.2 to
     2.0 transition.

   - removal of unused DIO flags from Nikolay.

   - blk-mq/sbitmap memory ordering fixes from Omar.

   - divide-by-zero fix for BFQ from Paolo.

   - minor documentation patches from Randy.

   - timeout fix from Tejun.

   - Alpha "can't write a char atomically" fix from Mikulas.

   - set of NVMe fixes by way of Keith.

   - bsg and bsg-lib improvements from Christoph.

   - a few sed-opal fixes from Jonas.

   - cdrom check-disk-change deadlock fix from Maurizio.

   - various little fixes, comment fixes, etc from various folks"

* tag 'for-4.17/block-20180402' of git://git.kernel.dk/linux-block: (139 commits)
  blk-mq: Directly schedule q->timeout_work when aborting a request
  blktrace: fix comment in blktrace_api.h
  lightnvm: remove function name in strings
  lightnvm: pblk: remove some unnecessary NULL checks
  lightnvm: pblk: don't recover unwritten lines
  lightnvm: pblk: implement 2.0 support
  lightnvm: pblk: implement get log report chunk
  lightnvm: pblk: rename ppaf* to addrf*
  lightnvm: pblk: check for supported version
  lightnvm: implement get log report chunk helpers
  lightnvm: make address conversions depend on generic device
  lightnvm: add support for 2.0 address format
  lightnvm: normalize geometry nomenclature
  lightnvm: complete geo structure with maxoc*
  lightnvm: add shorten OCSSD version in geo
  lightnvm: add minor version to generic geometry
  lightnvm: simplify geometry structure
  lightnvm: pblk: refactor init/exit sequences
  lightnvm: Avoid validation of default op value
  lightnvm: centralize permission check for lightnvm ioctl
  ...

Pull EDAC updates from Borislav Petkov:
 "Noteworthy is the NVDIMM support:

   - NVDIMM support to EDAC (Tony Luck)

   - misc fixes"

* tag 'edac_for_4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp:
  EDAC, sb_edac: Remove variable length array usage
  EDAC, skx_edac: Detect non-volatile DIMMs
  firmware, DMI: Add function to look up a handle and return DIMM size
  acpi, nfit: Add function to look up nvdimm device and provide SMBIOS handle
  EDAC: Add new memory type for non-volatile DIMMs
  EDAC: Drop duplicated array of strings for memory type names
  EDAC, layerscape: Allow building for LS1021A

In the effort to remove all VLAs from the kernel[1], it is desirable to
build with -Wvla.  However, this warning is overly pessimistic, in that
it is only happy with stack array sizes that are declared as constant
expressions, and not constant values.  One case of this is the
evaluation of the max() macro which, due to its construction, ends up
converting constant expression arguments into a constant value result.

All attempts to rewrite this macro with __builtin_constant_p() failed
with older compilers (e.g.  gcc 4.4)[2].  However, Martin Uecker,
constructed[3] a mind-shattering solution that works everywhere.
Cthulhu fhtagn!

This patch updates the min()/max() macros to evaluate to a constant
expression when called on constant expression arguments.  This removes
several false-positive stack VLA warnings from an x86 allmodconfig build
when -Wvla is added:

  $ diff -u before.txt after.txt | grep ^-
  -drivers/input/touchscreen/cyttsp4_core.c:871:2: warning: ISO C90 forbids variable length array ‘ids’ [-Wvla]
  -fs/btrfs/tree-checker.c:344:4: warning: ISO C90 forbids variable length array ‘namebuf’ [-Wvla]
  -lib/vsprintf.c:747:2: warning: ISO C90 forbids variable length array ‘sym’ [-Wvla]
  -net/ipv4/proc.c:403:2: warning: ISO C90 forbids variable length array ‘buff’ [-Wvla]
  -net/ipv6/proc.c:198:2: warning: ISO C90 forbids variable length array ‘buff’ [-Wvla]
  -net/ipv6/proc.c:218:2: warning: ISO C90 forbids variable length array ‘buff64’ [-Wvla]

This also updates two cases where different enums were being compared
and explicitly casts them to int (which matches the old side-effect of
the single-evaluation code): one in tpm/tpm_tis_core.h, and one in
drm/drm_color_mgmt.c.

 [1] https://lkml.org/lkml/2018/3/7/621
 [2] https://lkml.org/lkml/2018/3/10/170
 [3] https://lkml.org/lkml/2018/3/20/845



Co-Developed-by: Linus Torvalds <torvalds@linux-foundation.org>
Co-Developed-by: Martin Uecker <Martin.Uecker@med.uni-goettingen.de>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull input updates from Dmitry Torokhov:

 - new driver for PhoenixRC Flight Controller Adapter

 - new driver for RAVE SP Power button

 - fixes for autosuspend-related deadlocks in a few unput USB dirvers

 - support for 2nd wheel in ATech PS/2 mouse

 - fix for ALPS trackpoint detection on Thinkpad L570 and Latitude 7370

 - bunch of cleanups in various in PS/2 protocols

 - other assorted changes and fixes

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (35 commits)
  Input: i8042 - enable MUX on Sony VAIO VGN-CS series to fix touchpad
  Input: stmfts, s6sy761 - update my e-mail
  Input: stmfts - use async probe & suspend/resume to avoid 2s delay
  Input: ALPS - fix TrackStick detection on Thinkpad L570 and Latitude 7370
  Input: xpad - add PDP device id 0x02a4
  Input: alps - report pressure of v3 and v7 trackstick
  Input: pxrc - new driver for PhoenixRC Flight Controller Adapter
  Input: usbtouchscreen - do not rely on input_dev->users
  Input: usbtouchscreen - fix deadlock in autosuspend
  Input: pegasus_notetaker - do not rely on input_dev->users
  Input: pagasus_notetaker - fix deadlock in autosuspend
  Input: synaptics_usb - do not rely on input_dev->users
  Input: synaptics_usb - fix deadlock in autosuspend
  Input: gpio-keys - add support for wakeup event action
  Input: appletouch - use true and false for boolean values
  Input: silead - add Chuwi Hi8 support
  Input: analog - use get_cycles() on PPC
  Input: stmpe-keypad - remove VLA usage
  Input: i8042 - add Lenovo ThinkPad L460 to i8042 reset list
  Input: add RAVE SP Powerbutton driver
  ...

Pull trivial tree updates from Jiri Kosina.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial:
  kfifo: fix inaccurate comment
  tools/thermal: tmon: fix for segfault
  net: Spelling s/stucture/structure/
  edd: don't spam log if no EDD information is present
  Documentation: Fix early-microcode.txt references after file rename
  tracing: Block comments should align the * on each line
  treewide: Fix typos in printk
  GenWQE: Fix a typo in two comments
  treewide: Align function definition open/close braces

Pull HID updates from Jiri Kosina:

 - 3rd generation Wacom Intuos BT device support from Aaron Armstrong
   Skomra

 - support for NSG-MR5U and NSG-MR7U devices from Todd Kelner

 - multitouch Razer Blade Stealth support from Benjamin Tissoires

 - Elantech touchpad support from Alexandrov Stansilav

 - a few other scattered-around fixes and cleanups to drivers and
   generic code

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid: (31 commits)
  HID: google: Enable PM Full On mode when adjusting backlight
  HID: google: add google hammer HID driver
  HID: core: reset the quirks before calling probe again
  HID: multitouch: do not set HID_QUIRK_NO_INIT_REPORTS
  HID: core: remove the need for HID_QUIRK_NO_EMPTY_INPUT
  HID: use BIT() macro for quirks too
  HID: use BIT macro instead of plain integers for flags
  HID: multitouch: remove dead zones of Razer Blade Stealth
  HID: multitouch: export a quirk for the button handling of touchpads
  HID: usbhid: extend the polling interval configuration to keyboards
  HID: ntrig: document sysfs interface
  HID: wacom: wacom_wac_collection() is local to wacom_wac.c
  HID: wacom: generic: add the "Report Valid" usage
  HID: wacom: generic: Support multiple tools per report
  HID: wacom: Add support for 3rd generation Intuos BT
  HID: core: rewrite the hid-generic automatic unbind
  HID: sony: Add touchpad support for NSG-MR5U and NSG-MR7U remotes
  HID: hid-multitouch: Use true and false for boolean values
  HID: hid-ntrig: use true and false for boolean values
  HID: logitech-hidpp: document sysfs interface
  ...

Pull sound updates from Takashi Iwai:
 "This became a large update. The changes are scattered widely, and the
  majority of them are attributed to ASoC componentization. The gitk
  output made me dizzy, but it's slightly better than London tube.

  OK, below are some highlights:

   - Continued hardening works in ALSA PCM core; most of the existing
     syzkaller reports should have been covered.

   - USB-audio got the initial USB Audio Class 3 support, as well as
     UAC2 jack detection support and more DSD-device support.

   - ASoC componentization: finally each individual driver was converted
     to components framework, which is more future-proof for further
     works. Most of conversations were systematic.

   - Lots of fixes for Intel Baytrail / Cherrytrail devices with Realtek
     codecs, typically tablets and small PCs.

   - Fixes / cleanups for Samsung Odroid systems

   - Cleanups in Freescale SSI driver

   - New ASoC drivers:
      * AKM AK4458 and AK5558 codecs
      * A few AMD based machine drivers
      * Intel Kabylake machine drivers
      * Maxim MAX9759 codec
      * Motorola CPCAP codec
      * Socionext Uniphier SoCs
      * TI PCM1789 and TDA7419 codecs

   - Retirement of Blackfin drivers along with architecture removal"

* tag 'sound-4.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (497 commits)
  ALSA: pcm: Fix UAF at PCM release via PCM timer access
  ALSA: usb-audio: silence a static checker warning
  ASoC: tscs42xx: Remove owner assignment from i2c_driver
  ASoC: mediatek: remove "simple-mfd" in the example
  ASoC: cpcap: replace codec to component
  ASoC: Intel: bytcr_rt5651: don't use codec anymore
  ASoC: amd: don't use codec anymore
  ALSA: usb-audio: fix memory leak on cval
  ALSA: pcm: Fix mutex unbalance in OSS emulation ioctls
  ASoC: topology: Fix kcontrol name string handling
  ALSA: aloop: Mark paused device as inactive
  ALSA: usb-audio: update clock valid control
  ALSA: usb-audio: UAC2 jack detection
  ALSA: pcm: Return -EBUSY for OSS ioctls changing busy streams
  ALSA: pcm: Avoid potential races between OSS ioctls and read/write
  ALSA: usb-audio: Integrate native DSD support for ITF-USB based DACs.
  ALSA: usb-audio: FIX native DSD support for TEAC UD-501 DAC
  ALSA: usb-audio: Add native DSD support for Luxman DA-06
  ALSA: usb-audio: fix uac control query argument
  ASoC: nau8824: recover system clock when device changes
  ...

Pull dma-mapping updates from Christoph Hellwig:
 "Very light this round as the interesting dma mapping changes went
  through the x86 tree.

  This just provides proper stubs for architectures not supporting dma
  (Geert Uytterhoeven)"

* tag 'dma-mapping-4.17' of git://git.infradead.org/users/hch/dma-mapping:
  usb: gadget: Add NO_DMA dummies for DMA mapping API
  scsi: Add NO_DMA dummies for SCSI DMA mapping API
  mm: Add NO_DMA dummies for DMA pool API
  dma-coherent: Add NO_DMA dummies for managed DMA API
  dma-mapping: Convert NO_DMA get_dma_ops() into a real dummy

Pull GPIO updates from Linus Walleij:
 "This is the bulk of GPIO changes for the v4.17 kernel cycle:

  New drivers:

   - Nintendo Wii GameCube GPIO, known as "Hollywood"

   - Raspberry Pi mailbox service GPIO expander

   - Spreadtrum main SC9860 SoC and IEC GPIO controllers.

  Improvements:

   - Implemented .get_multiple() callback for most of the
     high-performance industrial GPIO cards for the ISA bus.

   - ISA GPIO drivers now select the ISA_BUS_API instead of depending on
     it. This is merged with the same pattern for all the ISA drivers
     and some other Kconfig cleanups related to this.

  Cleanup:

   - Delete the TZ1090 GPIO drivers following the deletion of this SoC
     from the ARM tree.

   - Move the documentation over to driver-api to conform with the rest
     of the kernel documentation build.

   - Continue to make the GPIO drivers include only
     <linux/gpio/driver.h> and not the too broad <linux/gpio.h> that we
     want to get rid of.

   - Managed to remove VLA allocation from two drivers pending more
     fixes in this area for the next merge window.

   - Misc janitorial fixes"

* tag 'gpio-v4.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (77 commits)
  gpio: Add Spreadtrum PMIC EIC driver support
  gpio: Add Spreadtrum EIC driver support
  dt-bindings: gpio: Add Spreadtrum EIC controller documentation
  gpio: ath79: Fix potential NULL dereference in ath79_gpio_probe()
  pinctrl: qcom: Don't allow protected pins to be requested
  gpiolib: Support 'gpio-reserved-ranges' property
  gpiolib: Change bitmap allocation to kmalloc_array
  gpiolib: Extract mask allocation into subroutine
  dt-bindings: gpio: Add a gpio-reserved-ranges property
  gpio: mockup: fix a potential crash when creating debugfs entries
  gpio: pca953x: add compatibility for pcal6524 and pcal9555a
  gpio: dwapb: Add support for a bus clock
  gpio: Remove VLA from xra1403 driver
  gpio: Remove VLA from MAX3191X driver
  gpio: ws16c48: Implement get_multiple callback
  gpio: gpio-mm: Implement get_multiple callback
  gpio: 104-idi-48: Implement get_multiple callback
  gpio: 104-dio-48e: Implement get_multiple callback
  gpio: pcie-idio-24: Implement get_multiple/set_multiple callbacks
  gpio: pci-idio-16: Implement get_multiple callback
  ...

Pull support for 3rd generation Intuos BT device

Pull a few small generic code cleanups.