For blk-mq, we need to be able to iterate software queues starting
from any queue in a round robin fashion, so introduce this helper.
Reviewed-by: NOmar Sandoval <osandov@fb.com>
Cc: Omar Sandoval <osandov@fb.com>
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Since we now lookup elevator types with the appropriate multiqueue
capability, allow schedulers to register with an alias alongside
the real name. This is in preparation for allowing 'mq-deadline'
to register an alias of 'deadline' as well.
Reviewed-by: NOmar Sandoval <osandov@fb.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Implement a generic path for sending sync I/O on LightNVM. This allows
to reuse the standard synchronous path trough blk_execute_rq(), instead
of implementing a wait_for_completion on the target side (e.g., pblk).
Signed-off-by: NJavier González <javier@cnexlabs.com>
Signed-off-by: NMatias Bjørling <m@bjorling.me>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Not all exported symbols are being used outside core and there were
some stale entries in lightnvm.h
Signed-off-by: NRakesh Pandit <rakesh@tuxera.com>
Signed-off-by: NMatias Bjørling <m@bjorling.me>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

vblk isn't being used anyway and if we ever have a usecase we can
introduce this again.  This makes the logic easier and removes
unnecessary checks.
Signed-off-by: NRakesh Pandit <rakesh@tuxera.com>
Signed-off-by: NMatias Bjørling <m@bjorling.me>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

If target type module e.g. pblk here is unloaded (rmmod) while module
is in use (after creating target) system crashes.  We fix this by
using module API refcnt.
Signed-off-by: NRakesh Pandit <rakesh@tuxera.com>
Signed-off-by: NMatias Bjørling <m@bjorling.me>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Replaced by pr_err usage in commit ef510424 ("block, dax: move
"select DAX" from BLOCK to FS_DAX")
Signed-off-by: NRakesh Pandit <rakesh@tuxera.com>
Acked-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Fix two issues:
- the per-cpu stat flush is unnecessary, nobody uses per-cpu stat except
  sum it to global stat. We can do the calculation there. The flush just
  wastes cpu time.
- some fields are signed int/s64. I don't see the point.
Reviewed-by: NOmar Sandoval <osandov@fb.com>
Signed-off-by: NShaohua Li <shli@fb.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Since commit 925a6efb ("Btrfs: stop using
try_to_writeback_inodes_sb_nr to flush delalloc") this function hasn't
been used outside so stop exporting it.

In addition we merge it into try_to_writeback_inodes_sb() which is the
only caller.  Also change return type of try_to_writeback_inodes_sb to
void as the only user ext4 doesn't care.
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NRakesh Pandit <rakesh@tuxera.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

After commit b35bd0d9, pdflush_proc_obsolete() is no longer
used. Kill the function and declaration.
Reported-by: NRakesh Pandit <rakesh@tuxera.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

We already have a queue_is_rq_based helper to check if a request_queue
is request based, so we can remove the flag for it.
Acked-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Handle start-all writeback like we do periodic or kupdate
style writeback - by marking the bdi_writeback as needing a full
flush, and simply waking the thread. This eliminates the need to
allocate and queue a specific work item just for this purpose.

After this change, we truly only ever have one of them running at
any point in time. We mark the need to start all flushes, and the
writeback thread will clear it once it has processed the request.
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

When someone calls wakeup_flusher_threads() or
wakeup_flusher_threads_bdi(), they schedule writeback of all dirty
pages in the system (or on that bdi). If we are tight on memory, we
can get tons of these queued from kswapd/vmscan. This causes (at
least) two problems:

1) We consume a ton of memory just allocating writeback work items.
   We've seen as much as 600 million of these writeback work items
   pending. That's a lot of memory to pointlessly hold hostage,
   while the box is under memory pressure.

2) We spend so much time processing these work items, that we
   introduce a softlockup in writeback processing. This is because
   each of the writeback work items don't end up doing any work (it's
   hard when you have millions of identical ones coming in to the
   flush machinery), so we just sit in a tight loop pulling work
   items and deleting/freeing them.

Fix this by adding a 'start_all' bit to the writeback structure, and
set that when someone attempts to flush all dirty pages. The bit is
cleared when we start writeback on that work item. If the bit is
already set when we attempt to queue !nr_pages writeback, then we
simply ignore it.

This provides us one full flush in flight, with one pending as well,
and makes for more efficient handling of this type of writeback.
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Tested-by: NChris Mason <clm@fb.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

We don't have any callers outside of fs-writeback.c anymore,
make it private.
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Tested-by: NChris Mason <clm@fb.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Similar to wakeup_flusher_threads(), except that we only wake
up the flusher threads on the specified backing device.

No functional changes in this patch.
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Tested-by: NChris Mason <clm@fb.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

All the callers pass in 'true' for range_cyclic, so kill the
argument.
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Everybody is passing in 0 now, let's get rid of the argument.
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Instead of adding weird retry logic in that function, utilize
__GFP_NOFAIL to ensure that the vm takes care of handling any
potential retries appropriately. This means we don't have to
call free_more_memory() from here.
Reviewed-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The code is only for blkcg not for all cgroups

Fixes: d4478e92 ("block/loop: make loop cgroup aware")
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NShaohua Li <shli@fb.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

bio_blkcg is the only API to get cgroup info for a bio right now. If
bio_blkcg finds current task is a kthread and has original blkcg
associated, it will use the css instead of associating the bio to
current task. This makes it possible that kthread dispatches bios on
behalf of other threads.
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NShaohua Li <shli@fb.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Nobody uses the APIs right now.
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NShaohua Li <shli@fb.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

kthread usually runs jobs on behalf of other threads. The jobs should be
charged to cgroup of original threads. But the jobs run in a kthread,
where we lose the cgroup context of original threads. The patch adds a
machanism to record cgroup info of original threads in kthread context.
Later we can retrieve the cgroup info and attach the cgroup info to jobs.

Since this mechanism is only required by kthread, we store the cgroup
info in kthread data instead of generic task_struct.
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NShaohua Li <shli@fb.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Comments were incorrect:
- defer_rcv was in host port template. moved to target port template
- Added Mandatory statements for target port template items
Signed-off-by: NJames Smart <james.smart@broadcom.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Add transport SGL defintions from NVMe TP 4008, required for
the final NVMe-FC standard.
Signed-off-by: NJames Smart <james.smart@broadcom.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The NVM express group recinded the reserved range for the transport.
Remove the FC-centric values that had been defined.
Signed-off-by: NJames Smart <james.smart@broadcom.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The lockdep code had reported the following unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(s_active#228);
                               lock(&bdev->bd_mutex/1);
                               lock(s_active#228);
  lock(&bdev->bd_mutex);

 *** DEADLOCK ***

The deadlock may happen when one task (CPU1) is trying to delete a
partition in a block device and another task (CPU0) is accessing
tracing sysfs file (e.g. /sys/block/dm-1/trace/act_mask) in that
partition.

The s_active isn't an actual lock. It is a reference count (kn->count)
on the sysfs (kernfs) file. Removal of a sysfs file, however, require
a wait until all the references are gone. The reference count is
treated like a rwsem using lockdep instrumentation code.

The fact that a thread is in the sysfs callback method or in the
ioctl call means there is a reference to the opended sysfs or device
file. That should prevent the underlying block structure from being
removed.

Instead of using bd_mutex in the block_device structure, a new
blk_trace_mutex is now added to the request_queue structure to protect
access to the blk_trace structure.
Suggested-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NWaiman Long <longman@redhat.com>
Acked-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>

Fix typo in patch subject line, and prune a comment detailing how
the code used to work.
Signed-off-by: NJens Axboe <axboe@kernel.dk>

In linux-4.13, Wei worked hard to convert dst to a traditional
refcounted model, removing GC.

We now want to make sure a dst refcount can not transition from 0 back
to 1.

The problem here is that input path attached a not refcounted dst to an
skb. Then later, because packet is forwarded and hits skb_dst_force()
before exiting RCU section, we might try to take a refcount on one dst
that is about to be freed, if another cpu saw 1 -> 0 transition in
dst_release() and queued the dst for freeing after one RCU grace period.

Lets unify skb_dst_force() and skb_dst_force_safe(), since we should
always perform the complete check against dst refcount, and not assume
it is not zero.

Bugzilla : https://bugzilla.kernel.org/show_bug.cgi?id=197005

[  989.919496]  skb_dst_force+0x32/0x34
[  989.919498]  __dev_queue_xmit+0x1ad/0x482
[  989.919501]  ? eth_header+0x28/0xc6
[  989.919502]  dev_queue_xmit+0xb/0xd
[  989.919504]  neigh_connected_output+0x9b/0xb4
[  989.919507]  ip_finish_output2+0x234/0x294
[  989.919509]  ? ipt_do_table+0x369/0x388
[  989.919510]  ip_finish_output+0x12c/0x13f
[  989.919512]  ip_output+0x53/0x87
[  989.919513]  ip_forward_finish+0x53/0x5a
[  989.919515]  ip_forward+0x2cb/0x3e6
[  989.919516]  ? pskb_trim_rcsum.part.9+0x4b/0x4b
[  989.919518]  ip_rcv_finish+0x2e2/0x321
[  989.919519]  ip_rcv+0x26f/0x2eb
[  989.919522]  ? vlan_do_receive+0x4f/0x289
[  989.919523]  __netif_receive_skb_core+0x467/0x50b
[  989.919526]  ? tcp_gro_receive+0x239/0x239
[  989.919529]  ? inet_gro_receive+0x226/0x238
[  989.919530]  __netif_receive_skb+0x4d/0x5f
[  989.919532]  netif_receive_skb_internal+0x5c/0xaf
[  989.919533]  napi_gro_receive+0x45/0x81
[  989.919536]  ixgbe_poll+0xc8a/0xf09
[  989.919539]  ? kmem_cache_free_bulk+0x1b6/0x1f7
[  989.919540]  net_rx_action+0xf4/0x266
[  989.919543]  __do_softirq+0xa8/0x19d
[  989.919545]  irq_exit+0x5d/0x6b
[  989.919546]  do_IRQ+0x9c/0xb5
[  989.919548]  common_interrupt+0x93/0x93
[  989.919548]  </IRQ>

Similarly dst_clone() can use dst_hold() helper to have additional
debugging, as a follow up to commit 44ebe791 ("net: add debug
atomic_inc_not_zero() in dst_hold()")

In net-next we will convert dst atomic_t to refcount_t for peace of
mind.

Fixes: a4c2fd7f ("net: remove DST_NOCACHE flag")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Wei Wang <weiwan@google.com>
Reported-by: NPaweł Staszewski <pstaszewski@itcare.pl>
Bisected-by: NPaweł Staszewski <pstaszewski@itcare.pl>
Acked-by: NWei Wang <weiwan@google.com>
Acked-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Normally, when input device supporting force feedback effects is being
destroyed, we try to "flush" currently playing effects, so that the
physical device does not continue vibrating (or executing other effects).
Unfortunately this does not work well for uinput as flushing of the effects
deadlocks with the destroy action:

- if device is being destroyed because the file descriptor is being closed,
  then there is noone to even service FF requests;

- if device is being destroyed because userspace sent UI_DEV_DESTROY,
  while theoretically it could be possible to service FF requests,
  userspace is unlikely to do so (they'd need to make sure FF handling
  happens on a separate thread) even if kernel solves the issue with FF
  ioctls deadlocking with UI_DEV_DESTROY ioctl on udev->mutex.

To avoid lockups like the one below, let's install a custom input device
flush handler, and avoid trying to flush force feedback effects when we
destroying the device, and instead rely on uinput to shut off the device
properly.

NMI watchdog: Watchdog detected hard LOCKUP on cpu 3
...
 <<EOE>>  [<ffffffff817a0307>] _raw_spin_lock_irqsave+0x37/0x40
 [<ffffffff810e633d>] complete+0x1d/0x50
 [<ffffffffa00ba08c>] uinput_request_done+0x3c/0x40 [uinput]
 [<ffffffffa00ba587>] uinput_request_submit.part.7+0x47/0xb0 [uinput]
 [<ffffffffa00bb62b>] uinput_dev_erase_effect+0x5b/0x76 [uinput]
 [<ffffffff815d91ad>] erase_effect+0xad/0xf0
 [<ffffffff815d929d>] flush_effects+0x4d/0x90
 [<ffffffff815d4cc0>] input_flush_device+0x40/0x60
 [<ffffffff815daf1c>] evdev_cleanup+0xac/0xc0
 [<ffffffff815daf5b>] evdev_disconnect+0x2b/0x60
 [<ffffffff815d74ac>] __input_unregister_device+0xac/0x150
 [<ffffffff815d75f7>] input_unregister_device+0x47/0x70
 [<ffffffffa00bac45>] uinput_destroy_device+0xb5/0xc0 [uinput]
 [<ffffffffa00bb2de>] uinput_ioctl_handler.isra.9+0x65e/0x740 [uinput]
 [<ffffffff811231ab>] ? do_futex+0x12b/0xad0
 [<ffffffffa00bb3f8>] uinput_ioctl+0x18/0x20 [uinput]
 [<ffffffff81241248>] do_vfs_ioctl+0x298/0x480
 [<ffffffff81337553>] ? security_file_ioctl+0x43/0x60
 [<ffffffff812414a9>] SyS_ioctl+0x79/0x90
 [<ffffffff817a04ee>] entry_SYSCALL_64_fastpath+0x12/0x71
Reported-by: NRodrigo Rivas Costa <rodrigorivascosta@gmail.com>
Reported-by: NClément VUCHENER <clement.vuchener@gmail.com>
Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=193741Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

Commit 3f1ac7a7 ("net: ethtool: add new ETHTOOL_xLINKSETTINGS API")
deprecated the ethtool_cmd::transceiver field, which was fine in
premise, except that the PHY library was actually using it to report the
type of transceiver: internal or external.

Use the first word of the reserved field to put this __u8 transceiver
field back in. It is made read-only, and we don't expect the
ETHTOOL_xLINKSETTINGS API to be doing anything with this anyway, so this
is mostly for the legacy path where we do:

ethtool_get_settings()
-> dev->ethtool_ops->get_link_ksettings()
   -> convert_link_ksettings_to_legacy_settings()

to have no information loss compared to the legacy get_settings API.

Fixes: 3f1ac7a7 ("net: ethtool: add new ETHTOOL_xLINKSETTINGS API")
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit 74def747.

The change to the helper function is only correct for the /proc/irq/
readout usage, but breaks the existing x86 usage of that function.
Reported-by: NYanko Kaneti <yaneti@declera.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>

This patch fixes a bug exhibited by the following scenario:
  1. fd1 = perf_event_open with attr.config = ID1
  2. attach bpf program prog1 to fd1
  3. fd2 = perf_event_open with attr.config = ID1
     <this will be successful>
  4. user program closes fd2 and prog1 is detached from the tracepoint.
  5. user program with fd1 does not work properly as tracepoint
     no output any more.

The issue happens at step 4. Multiple perf_event_open can be called
successfully, but only one bpf prog pointer in the tp_event. In the
current logic, any fd release for the same tp_event will free
the tp_event->prog.

The fix is to free tp_event->prog only when the closing fd
corresponds to the one which registered the program.
Signed-off-by: NYonghong Song <yhs@fb.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Due to commit db3e50f3 (device property: Get rid of struct
fwnode_handle type field), ACPI_HANDLE() inadvertently became
a GPL-only call. The call path that led to that was:

ACPI_HANDLE()
    ACPI_COMPANION()
        to_acpi_device_node()
            is_acpi_device_node()
                acpi_device_fwnode_ops
                    DECLARE_ACPI_FWNODE_OPS(acpi_device_fwnode_ops);

...and the new DECLARE_ACPI_FWNODE_OPS() includes
EXPORT_SYMBOL_GPL, whereas previously it was a static struct.

In order to avoid changing any of that, let's instead provide ever
so slightly better encapsulation of those struct fwnode_operations
instances. Those do not really need to be directly used in
inline function calls in header files. Simply moving two small
functions (is_acpi_device_node and is_acpi_data_node) out of
acpi_bus.h, and into a .c file, does that.

That leaves the internals of struct fwnode_operations as GPL-only
(which I think was the intent all along), but un-breaks any driver
code out there that relies on the ACPI subsystem's being (historically)
an EXPORT_SYMBOL-usable system. By that, I mean, ACPI_HANDLE() and
other basic ACPI calls were non-GPL-protected.

Also, while I'm there, remove a tiny bit of redundancy that was missed
in the earlier commit, by having is_acpi_node() use the other two
routines, instead of checking fwnode directly.

Fixes: db3e50f3 (device property: Get rid of struct fwnode_handle type field)
Signed-off-by: NJohn Hubbard <jhubbard@nvidia.com>
Acked-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The ipmmu-vmsa driver fails in compile-testing on non-OF platforms:

drivers/iommu/ipmmu-vmsa.o: In function `ipmmu_of_xlate':
ipmmu-vmsa.c:(.text+0x740): undefined reference to `of_find_device_by_node'

It would be reasonable to assume that this interface works but
returns failure on non-OF builds, like it does on machines that
have been booted in another way, so this adds another inline
function helper.

Fixes: 7b2d5961 ("iommu/ipmmu-vmsa: Replace local utlb code with fwspec ids")
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NRob Herring <robh@kernel.org>

This is unused, and conflicts with the definition that we'll add for XPFO.
Signed-off-by: NTycho Andersen <tycho@docker.com>
Reviewed-by: NJulien Grall <julien.grall@arm.com>
CC: Boris Ostrovsky <boris.ostrovsky@oracle.com>
CC: Juergen Gross <jgross@suse.com>
CC: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>

remove tcp_may_send_now and tcp_snd_test that are no longer used

Fixes: 840a3cbe ("tcp: remove forward retransmit feature")
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Correct location as of commit 2728b2d2 (PM / core / docs:
Convert sleep states API document to reST).

Fixes: 2728b2d2 (PM / core / docs: Convert sleep states API document to reST)
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Use CHECK_DATA_CORRUPTION instead of BUG_ON to provide more flexibility
on address limit failures. By default, send a SIGKILL signal to kill the
current process preventing exploitation of a bad address limit.

Make the TIF_FSCHECK flag optional so ARM can use this function.
Signed-off-by: NThomas Garnier <thgarnie@google.com>
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Pratyush Anand <panand@redhat.com>
Cc: Dave Martin <Dave.Martin@arm.com>
Cc: Will Drewry <wad@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: David Howells <dhowells@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-api@vger.kernel.org
Cc: Yonghong Song <yhs@fb.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1504798247-48833-2-git-send-email-keescook@chromium.org

Commit 86fdb344 ("sctp: ensure ep is not destroyed before doing the
dump") tried to fix an use-after-free issue by checking !sctp_sk(sk)->ep
with holding sock and sock lock.

But Paolo noticed that endpoint could be destroyed in sctp_rcv without
sock lock protection. It means the use-after-free issue still could be
triggered when sctp_rcv put and destroy ep after sctp_sock_dump checks
!ep, although it's pretty hard to reproduce.

I could reproduce it by mdelay in sctp_rcv while msleep in sctp_close
and sctp_sock_dump long time.

This patch is to add another param cb_done to sctp_for_each_transport
and dump ep->assocs with holding tsp after jumping out of transport's
traversal in it to avoid this issue.

It can also improve sctp diag dump to make it run faster, as no need
to save sk into cb->args[5] and keep calling sctp_for_each_transport
any more.

This patch is also to use int * instead of int for the pos argument
in sctp_for_each_transport, which could make postion increment only
in sctp_for_each_transport and no need to keep changing cb->args[2]
in sctp_sock_filter and sctp_sock_dump any more.

Fixes: 86fdb344 ("sctp: ensure ep is not destroyed before doing the dump")
Reported-by: NPaolo Abeni <pabeni@redhat.com>
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Which is the equivalent of what we have in regular waitqueues.
I'm not crazy about the name, but this also helps us get both
apis closer -- which iirc comes originally from the -net folks.

We also duplicate the comments for the lockless swait_active(),
from wait.h. Future users will make use of this interface.
Signed-off-by: NDavidlohr Bueso <dbueso@suse.de>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This patch constifies the path argument to kernel_read_file_from_path().
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>