Currently, the bypass is flushed at the very last moment in the
deoffloading procedure. However, this approach leads to a larger state
space than would be preferred. This commit therefore disables the
bypass at soon as the deoffloading procedure begins, then flushes it.
This guarantees that the bypass remains empty and thus out of the way
of the deoffloading procedure.
Symmetrically, this commit waits to enable the bypass until the offloading
procedure has completed.
Reported-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
This sequence of events can lead to a failure to requeue a CPU's
->nocb_timer:
1. There are no callbacks queued for any CPU covered by CPU 0-2's
->nocb_gp_kthread. Note that ->nocb_gp_kthread is associated
with CPU 0.
2. CPU 1 enqueues its first callback with interrupts disabled, and
thus must defer awakening its ->nocb_gp_kthread. It therefore
queues its rcu_data structure's ->nocb_timer. At this point,
CPU 1's rdp->nocb_defer_wakeup is RCU_NOCB_WAKE.
3. CPU 2, which shares the same ->nocb_gp_kthread, also enqueues a
callback, but with interrupts enabled, allowing it to directly
awaken the ->nocb_gp_kthread.
4. The newly awakened ->nocb_gp_kthread associates both CPU 1's
and CPU 2's callbacks with a future grace period and arranges
for that grace period to be started.
5. This ->nocb_gp_kthread goes to sleep waiting for the end of this
future grace period.
6. This grace period elapses before the CPU 1's timer fires.
This is normally improbably given that the timer is set for only
one jiffy, but timers can be delayed. Besides, it is possible
that kernel was built with CONFIG_RCU_STRICT_GRACE_PERIOD=y.
7. The grace period ends, so rcu_gp_kthread awakens the
->nocb_gp_kthread, which in turn awakens both CPU 1's and
CPU 2's ->nocb_cb_kthread. Then ->nocb_gb_kthread sleeps
waiting for more newly queued callbacks.
8. CPU 1's ->nocb_cb_kthread invokes its callback, then sleeps
waiting for more invocable callbacks.
9. Note that neither kthread updated any ->nocb_timer state,
so CPU 1's ->nocb_defer_wakeup is still set to RCU_NOCB_WAKE.
10. CPU 1 enqueues its second callback, this time with interrupts
enabled so it can wake directly ->nocb_gp_kthread.
It does so with calling wake_nocb_gp() which also cancels the
pending timer that got queued in step 2. But that doesn't reset
CPU 1's ->nocb_defer_wakeup which is still set to RCU_NOCB_WAKE.
So CPU 1's ->nocb_defer_wakeup and its ->nocb_timer are now
desynchronized.
11. ->nocb_gp_kthread associates the callback queued in 10 with a new
grace period, arranges for that grace period to start and sleeps
waiting for it to complete.
12. The grace period ends, rcu_gp_kthread awakens ->nocb_gp_kthread,
which in turn wakes up CPU 1's ->nocb_cb_kthread which then
invokes the callback queued in 10.
13. CPU 1 enqueues its third callback, this time with interrupts
disabled so it must queue a timer for a deferred wakeup. However
the value of its ->nocb_defer_wakeup is RCU_NOCB_WAKE which
incorrectly indicates that a timer is already queued. Instead,
CPU 1's ->nocb_timer was cancelled in 10. CPU 1 therefore fails
to queue the ->nocb_timer.
14. CPU 1 has its pending callback and it may go unnoticed until
some other CPU ever wakes up ->nocb_gp_kthread or CPU 1 ever
calls an explicit deferred wakeup, for example, during idle entry.
This commit fixes this bug by resetting rdp->nocb_defer_wakeup everytime
we delete the ->nocb_timer.
It is quite possible that there is a similar scenario involving
->nocb_bypass_timer and ->nocb_defer_wakeup. However, despite some
effort from several people, a failure scenario has not yet been located.
However, that by no means guarantees that no such scenario exists.
Finding a failure scenario is left as an exercise for the reader, and the
"Fixes:" tag below relates to ->nocb_bypass_timer instead of ->nocb_timer.
Fixes: d1b222c6be (rcu/nocb: Add bypass callback queueing)
Cc: <stable@vger.kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Neeraj Upadhyay <neeraju@codeaurora.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
RCU triggerse the following sparse warning:
kernel/rcu/tree_plugin.h:1497:5: warning: symbol
'nocb_nobypass_lim_per_jiffy' was not declared. Should it be static?
This commit therefore makes this variable static.
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Reported-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
The name nocb_gp_update_state() is unenlightening, so this commit changes
it to nocb_gp_update_state_deoffloading(). This function now does what
its name says, updates state and returns true if the CPU corresponding to
the specified rcu_data structure is in the process of being de-offloaded.
Reported-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
At the start of a CPU-hotplug operation, the incoming CPU's callback
list can be in a number of states:
1. Disabled and empty. This is the case when the boot CPU has
not invoked call_rcu(), when a non-boot CPU first comes online,
and when a non-offloaded CPU comes back online. In this case,
it is both necessary and permissible to initialize ->cblist.
Because either the CPU is currently running with interrupts
disabled (boot CPU) or is not yet running at all (other CPUs),
it is not necessary to acquire ->nocb_lock.
In this case, initialization is required.
2. Disabled and non-empty. This cannot occur, because early boot
call_rcu() invocations enable the callback list before enqueuing
their callback.
3. Enabled, whether empty or not. In this case, the callback
list has already been initialized. This case occurs when the
boot CPU has executed an early boot call_rcu() and also when
an offloaded CPU comes back online. In both cases, there is
no need to initialize the callback list: In the boot-CPU case,
the CPU has not (yet) gone offline, and in the offloaded case,
the rcuo kthreads are taking care of business.
Because it is not necessary to initialize the callback list,
it is also not necessary to acquire ->nocb_lock.
Therefore, checking if the segcblist is enabled suffices. This commit
therefore initializes the callback list at rcutree_prepare_cpu() time
only if that list is disabled.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
The nocb_cb_wait() function first sets the rdp->nocb_cb_sleep flag to
true by after invoking the callbacks, and then sets it back to false if
it finds more callbacks that are ready to invoke.
This is confusing and will become unsafe if this flag is ever read
locklessly. This commit therefore writes it only once, based on the
state after both callback invocation and checking.
Reported-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
It makes no sense to de-offload an offline CPU because that CPU will never
invoke any remaining callbacks. It also makes little sense to offload an
offline CPU because any pending RCU callbacks were migrated when that CPU
went offline. Yes, it is in theory possible to use a number of tricks
to permit offloading and deoffloading offline CPUs in certain cases, but
in practice it is far better to have the simple and deterministic rule
"Toggling the offload state of an offline CPU is forbidden".
For but one example, consider that an offloaded offline CPU might have
millions of callbacks queued. Best to just say "no".
This commit therefore forbids toggling of the offloaded state of
offline CPUs.
Reported-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Provide CONFIG_PROVE_RCU sanity checks to ensure we are always reading
the offloaded state of an rdp in a safe and stable way and prevent from
its value to be changed under us. We must either hold the barrier mutex,
the cpu-hotplug lock (read or write) or the nocb lock.
Local non-preemptible reads are also safe. NOCB kthreads and timers have
their own means of synchronization against the offloaded state updaters.
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Pull rdma fixes from Jason Gunthorpe:
"Nothing special here, though Bob's regression fixes for rxe would have
made it before the rc cycle had there not been such strong winter
weather!
- Fix corner cases in the rxe reference counting cleanup that are
causing regressions in blktests for SRP
- Two kdoc fixes so W=1 is clean
- Missing error return in error unwind for mlx5
- Wrong lock type nesting in IB CM"
* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma:
RDMA/rxe: Fix errant WARN_ONCE in rxe_completer()
RDMA/rxe: Fix extra deref in rxe_rcv_mcast_pkt()
RDMA/rxe: Fix missed IB reference counting in loopback
RDMA/uverbs: Fix kernel-doc warning of _uverbs_alloc
RDMA/mlx5: Set correct kernel-doc identifier
IB/mlx5: Add missing error code
RDMA/rxe: Fix missing kconfig dependency on CRYPTO
RDMA/cm: Fix IRQ restore in ib_send_cm_sidr_rep
Pull gcc-plugins fixes from Kees Cook:
"Tiny gcc-plugin fixes for v5.12-rc2. These issues are small but have
been reported a couple times now by static analyzers, so best to get
them fixed to reduce the noise. :)
- Fix coding style issues (Jason Yan)"
* tag 'gcc-plugins-v5.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
gcc-plugins: latent_entropy: remove unneeded semicolon
gcc-plugins: structleak: remove unneeded variable 'ret'
Pull device mapper fixes from Mike Snitzer:
"Fix DM verity target's optional Forward Error Correction (FEC) for
Reed-Solomon roots that are unaligned to block size"
* tag 'for-5.12/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
dm verity: fix FEC for RS roots unaligned to block size
dm bufio: subtract the number of initial sectors in dm_bufio_get_device_size
Pull block fixes from Jens Axboe:
- NVMe fixes:
- more device quirks (Julian Einwag, Zoltán Böszörményi, Pascal
Terjan)
- fix a hwmon error return (Daniel Wagner)
- fix the keep alive timeout initialization (Martin George)
- ensure the model_number can't be changed on a used subsystem
(Max Gurtovoy)
- rsxx missing -EFAULT on copy_to_user() failure (Dan)
- rsxx remove unused linux.h include (Tian)
- kill unused RQF_SORTED (Jean)
- updated outdated BFQ comments (Joseph)
- revert work-around commit for bd_size_lock, since we removed the
offending user in this merge window (Damien)
* tag 'block-5.12-2021-03-05' of git://git.kernel.dk/linux-block:
nvmet: model_number must be immutable once set
nvme-fabrics: fix kato initialization
nvme-hwmon: Return error code when registration fails
nvme-pci: add quirks for Lexar 256GB SSD
nvme-pci: mark Kingston SKC2000 as not supporting the deepest power state
nvme-pci: mark Seagate Nytro XM1440 as QUIRK_NO_NS_DESC_LIST.
rsxx: Return -EFAULT if copy_to_user() fails
block/bfq: update comments and default value in docs for fifo_expire
rsxx: remove unused including <linux/version.h>
block: Drop leftover references to RQF_SORTED
block: revert "block: fix bd_size_lock use"
Pull io_uring fixes from Jens Axboe:
"A bit of a mix between fallout from the worker change, cleanups and
reductions now possible from that change, and fixes in general. In
detail:
- Fully serialize manager and worker creation, fixing races due to
that.
- Clean up some naming that had gone stale.
- SQPOLL fixes.
- Fix race condition around task_work rework that went into this
merge window.
- Implement unshare. Used for when the original task does unshare(2)
or setuid/seteuid and friends, drops the original workers and forks
new ones.
- Drop the only remaining piece of state shuffling we had left, which
was cred. Move it into issue instead, and we can drop all of that
code too.
- Kill f_op->flush() usage. That was such a nasty hack that we had
out of necessity, we no longer need it.
- Following from ->flush() removal, we can also drop various bits of
ctx state related to SQPOLL and cancelations.
- Fix an issue with IOPOLL retry, which originally was fallout from a
filemap change (removing iov_iter_revert()), but uncovered an issue
with iovec re-import too late.
- Fix an issue with system suspend.
- Use xchg() for fallback work, instead of cmpxchg().
- Properly destroy io-wq on exec.
- Add create_io_thread() core helper, and use that in io-wq and
io_uring. This allows us to remove various silly completion events
related to thread setup.
- A few error handling fixes.
This should be the grunt of fixes necessary for the new workers, next
week should be quieter. We've got a pending series from Pavel on
cancelations, and how tasks and rings are indexed. Outside of that,
should just be minor fixes. Even with these fixes, we're still killing
a net ~80 lines"
* tag 'io_uring-5.12-2021-03-05' of git://git.kernel.dk/linux-block: (41 commits)
io_uring: don't restrict issue_flags for io_openat
io_uring: make SQPOLL thread parking saner
io-wq: kill hashed waitqueue before manager exits
io_uring: clear IOCB_WAITQ for non -EIOCBQUEUED return
io_uring: don't keep looping for more events if we can't flush overflow
io_uring: move to using create_io_thread()
kernel: provide create_io_thread() helper
io_uring: reliably cancel linked timeouts
io_uring: cancel-match based on flags
io-wq: ensure all pending work is canceled on exit
io_uring: ensure that threads freeze on suspend
io_uring: remove extra in_idle wake up
io_uring: inline __io_queue_async_work()
io_uring: inline io_req_clean_work()
io_uring: choose right tctx->io_wq for try cancel
io_uring: fix -EAGAIN retry with IOPOLL
io-wq: fix error path leak of buffered write hash map
io_uring: remove sqo_task
io_uring: kill sqo_dead and sqo submission halting
io_uring: ignore double poll add on the same waitqueue head
...
Pull power management fixes from Rafael Wysocki:
"These fix the usage of device links in the runtime PM core code and
update the DTPM (Dynamic Thermal Power Management) feature added
recently.
Specifics:
- Make the runtime PM core code avoid attempting to suspend supplier
devices before updating the PM-runtime status of a consumer to
'suspended' (Rafael Wysocki).
- Fix DTPM (Dynamic Thermal Power Management) root node
initialization and label that feature as EXPERIMENTAL in Kconfig
(Daniel Lezcano)"
* tag 'pm-5.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
powercap/drivers/dtpm: Add the experimental label to the option description
powercap/drivers/dtpm: Fix root node initialization
PM: runtime: Update device status before letting suppliers suspend
Pull ACPI fix from Rafael Wysocki:
"Make the empty stubs of some helper functions used when CONFIG_ACPI is
not set actually match those functions (Andy Shevchenko)"
* tag 'acpi-5.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
ACPI: bus: Constify is_acpi_node() and friends (part 2)
Pull iommu fixes from Joerg Roedel:
- Fix a sleeping-while-atomic issue in the AMD IOMMU code
- Disable lazy IOTLB flush for untrusted devices in the Intel VT-d
driver
- Fix status code definitions for Intel VT-d
- Fix IO Page Fault issue in Tegra IOMMU driver
* tag 'iommu-fixes-v5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
iommu/vt-d: Fix status code for Allocate/Free PASID command
iommu: Don't use lazy flush for untrusted device
iommu/tegra-smmu: Fix mc errors on tegra124-nyan
iommu/amd: Fix sleeping in atomic in increase_address_space()
Pull btrfs fixes from David Sterba:
"More regression fixes and stabilization.
Regressions:
- zoned mode
- count zone sizes in wider int types
- fix space accounting for read-only block groups
- subpage: fix page tail zeroing
Fixes:
- fix spurious warning when remounting with free space tree
- fix warning when creating a directory with smack enabled
- ioctl checks for qgroup inheritance when creating a snapshot
- qgroup
- fix missing unlock on error path in zero range
- fix amount of released reservation on error
- fix flushing from unsafe context with open transaction,
potentially deadlocking
- minor build warning fixes"
* tag 'for-5.12-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: zoned: do not account freed region of read-only block group as zone_unusable
btrfs: zoned: use sector_t for zone sectors
btrfs: subpage: fix the false data csum mismatch error
btrfs: fix warning when creating a directory with smack enabled
btrfs: don't flush from btrfs_delayed_inode_reserve_metadata
btrfs: export and rename qgroup_reserve_meta
btrfs: free correct amount of space in btrfs_delayed_inode_reserve_metadata
btrfs: fix spurious free_space_tree remount warning
btrfs: validate qgroup inherit for SNAP_CREATE_V2 ioctl
btrfs: unlock extents in btrfs_zero_range in case of quota reservation errors
btrfs: ref-verify: use 'inline void' keyword ordering
Pull devicetree fixes from Rob Herring:
- Another batch of graph and video-interfaces schema conversions
- Drop DT header symlink for dropped C6X arch
- Fix bcm2711-hdmi schema error
* tag 'devicetree-fixes-for-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
dt-bindings: media: Use graph and video-interfaces schemas, round 2
dts: drop dangling c6x symlink
dt-bindings: bcm2711-hdmi: Fix broken schema
Pull tracing fixes from Steven Rostedt:
"Functional fixes:
- Fix big endian conversion for arm64 in recordmcount processing
- Fix timestamp corruption in ring buffer on discarding events
- Fix memory leak in __create_synth_event()
- Skip selftests if tracing is disabled as it will cause them to
fail.
Non-functional fixes:
- Fix help text in Kconfig
- Remove duplicate prototype for trace_empty()
- Fix stale comment about the trace_event_call flags.
Self test update:
- Add more information to the validation output of when a corrupt
timestamp is found in the ring buffer, and also trigger a warning
to make sure that tests catch it"
* tag 'trace-v5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Fix comment about the trace_event_call flags
tracing: Skip selftests if tracing is disabled
tracing: Fix memory leak in __create_synth_event()
ring-buffer: Add a little more information and a WARN when time stamp going backwards is detected
ring-buffer: Force before_stamp and write_stamp to be different on discard
tracing: Fix help text of TRACEPOINT_BENCHMARK in Kconfig
tracing: Remove duplicate declaration from trace.h
ftrace: Have recordmcount use w8 to read relp->r_info in arm64_is_fake_mcount
In rxe_comp.c in rxe_completer() the function free_pkt() did not clear skb
which triggered a warning at 'done:' and could possibly at 'exit:'. The
WARN_ONCE() calls are not actually needed. The call to free_pkt() is
moved to the end to clearly show that all skbs are freed.
Fixes: 899aba891c ("RDMA/rxe: Fix FIXME in rxe_udp_encap_recv()")
Link: https://lore.kernel.org/r/20210304192048.2958-1-rpearson@hpe.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
When the noted patch below extending the reference taken by
rxe_get_dev_from_net() in rxe_udp_encap_recv() until each skb is freed it
was not matched by a reference in the loopback path resulting in
underflows.
Fixes: 899aba891c ("RDMA/rxe: Fix FIXME in rxe_udp_encap_recv()")
Link: https://lore.kernel.org/r/20210304192048.2958-1-rpearson@hpe.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
45d189c606 ("io_uring: replace force_nonblock with flags") did
something strange for io_openat() slicing all issue_flags but
IO_URING_F_NONBLOCK. Not a bug for now, but better to just forward the
flags.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull NVMe fixes from Christoph:
"nvme fixes for 5.12:
- more device quirks (Julian Einwag, Zoltán Böszörményi, Pascal Terjan)
- fix a hwmon error return (Daniel Wagner)
- fix the keep alive timeout initialization (Martin George)
- ensure the model_number can't be changed on a used subsystem
(Max Gurtovoy)"
* tag 'nvme-5.12-2021-03-05' of git://git.infradead.org/nvme:
nvmet: model_number must be immutable once set
nvme-fabrics: fix kato initialization
nvme-hwmon: Return error code when registration fails
nvme-pci: add quirks for Lexar 256GB SSD
nvme-pci: mark Kingston SKC2000 as not supporting the deepest power state
nvme-pci: mark Seagate Nytro XM1440 as QUIRK_NO_NS_DESC_LIST.
We have this weird true/false return from parking, and then some of the
callers decide to look at that. It can lead to unbalanced parks and
sqd locking. Have the callers check the thread status once it's parked.
We know we have the lock at that point, so it's either valid or it's NULL.
Fix race with parking on thread exit. We need to be careful here with
ordering of the sdq->lock and the IO_SQ_THREAD_SHOULD_PARK bit.
Rename sqd->completion to sqd->parked to reflect that this is the only
thing this completion event doesn.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
If we race with shutting down the io-wq context and someone queueing
a hashed entry, then we can exit the manager with it armed. If it then
triggers after the manager has exited, we can have a use-after-free where
io_wqe_hash_wake() attempts to wake a now gone manager process.
Move the killing of the hashed write queue into the manager itself, so
that we know we've killed it before the task exits.
Fixes: e941894eae ("io-wq: make buffered file write hashed work map per-ctx")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The callback can only be armed, if we get -EIOCBQUEUED returned. It's
important that we clear the WAITQ bit for other cases, otherwise we can
queue for async retry and filemap will assume that we're armed and
return -EAGAIN instead of just blocking for the IO.
Cc: stable@vger.kernel.org # 5.9+
Signed-off-by: Jens Axboe <axboe@kernel.dk>
It doesn't make sense to wait for more events to come in, if we can't
even flush the overflow we already have to the ring. Return -EBUSY for
that condition, just like we do for attempts to submit with overflow
pending.
Cc: stable@vger.kernel.org # 5.11
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This allows us to do task creation and setup without needing to use
completions to try and synchronize with the starting thread. Get rid of
the old io_wq_fork_thread() wrapper, and the 'wq' and 'worker' startup
completion events - we can now do setup before the task is running.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
In case we have already established connection to nvmf target, it
shouldn't be allowed to change the model_number. E.g. if someone will
identify ctrl and get model_number of "my_model" later on will change
the model_numbel via configfs to "my_new_model" this will break the NVMe
specification for "Get Log Page – Persistent Event Log" that refers to
Model Number as: "This field contains the same value as reported in the
Model Number field of the Identify Controller data structure, bytes
63:24."
Although it doesn't mentioned explicitly that this field can't be
changed, we can assume it.
So allow setting this field only once: using configfs or in the first
identify ctrl operation.
Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Currently kato is initialized to NVME_DEFAULT_KATO for both
discovery & i/o controllers. This is a problem specifically
for non-persistent discovery controllers since it always ends
up with a non-zero kato value. Fix this by initializing kato
to zero instead, and ensuring various controllers are assigned
appropriate kato values as follows:
non-persistent controllers - kato set to zero
persistent controllers - kato set to NVMF_DEV_DISC_TMO
(or any positive int via nvme-cli)
i/o controllers - kato set to NVME_DEFAULT_KATO
(or any positive int via nvme-cli)
Signed-off-by: Martin George <marting@netapp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
The hwmon pointer wont be NULL if the registration fails. Though the
exit code path will assign it to ctrl->hwmon_device. Later
nvme_hwmon_exit() will try to free the invalid pointer. Avoid this by
returning the error code from hwmon_device_register_with_info().
Fixes: ed7770f662 ("nvme/hwmon: rework to avoid devm allocation")
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
My 2TB SKC2000 showed the exact same symptoms that were provided
in 538e4a8c57 ("nvme-pci: avoid the deepest sleep state on
Kingston A2000 SSDs"), i.e. a complete NVME lockup that needed
cold boot to get it back.
According to some sources, the A2000 is simply a rebadged
SKC2000 with a slightly optimized firmware.
Adding the SKC2000 PCI ID to the quirk list with the same workaround
as the A2000 made my laptop survive a 5 hours long Yocto bootstrap
buildfest which reliably triggered the SSD lockup previously.
Signed-off-by: Zoltán Böszörményi <zboszor@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Pull drm fixes from Dave Airlie:
"More may show up but this is what I have at this stage: just a single
nouveau regression fix, and a bunch of amdgpu fixes.
amdgpu:
- S0ix fix
- Handle new NV12 SKU
- Misc power fixes
- Display uninitialized value fix
- PCIE debugfs register access fix
nouveau:
- regression fix for gk104"
* tag 'drm-fixes-2021-03-05' of git://anongit.freedesktop.org/drm/drm:
drm/amdgpu: fix parameter error of RREG32_PCIE() in amdgpu_regs_pcie
drm/amd/display: fix the return of the uninitialized value in ret
drm/amdgpu: enable BACO runpm by default on sienna cichlid and navy flounder
drm/amd/pm: correct Arcturus mmTHM_BACO_CNTL register address
drm/amdgpu/swsmu/vangogh: Only use RLCPowerNotify msg for disable
drm/amdgpu/pm: make unsupported power profile messages debug
drm/amdgpu:disable VCN for Navi12 SKU
drm/amdgpu: Only check for S0ix if AMD_PMC is configured
drm/nouveau/fifo/gk104-gp1xx: fix creation of sw class
Pull iSCSI fixes from Martin Petersen:
"Three fixes for missed iSCSI verification checks (and make the sysfs
files use "sysfs_emit()" - that's what it is there for)"
* tag 'mkp-scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi:
scsi: iscsi: Verify lengths on passthrough PDUs
scsi: iscsi: Ensure sysfs attributes are limited to PAGE_SIZE
scsi: iscsi: Restrict sessions and handles to admin capabilities
Protect the iSCSI transport handle, available in sysfs, by requiring
CAP_SYS_ADMIN to read it. Also protect the netlink socket by restricting
reception of messages to ones sent with CAP_SYS_ADMIN. This disables
normal users from being able to end arbitrary iSCSI sessions.
Cc: stable@vger.kernel.org
Reported-by: Adam Nichols <adam@grimm-co.com>
Reviewed-by: Chris Leech <cleech@redhat.com>
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Lee Duncan <lduncan@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Provide a generic helper for setting up an io_uring worker. Returns a
task_struct so that the caller can do whatever setup is needed, then call
wake_up_new_task() to kick it into gear.
Add a kernel_clone_args member, io_thread, which tells copy_process() to
mark the task with PF_IO_WORKER.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Linked timeouts are fired asynchronously (i.e. soft-irq), and use
generic cancellation paths to do its stuff, including poking into io-wq.
The problem is that it's racy to access tctx->io_wq, as
io_uring_task_cancel() and others may be happening at this exact moment.
Mark linked timeouts with REQ_F_INLIFGHT for now, making sure there are
no timeouts before io-wq destraction.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Instead of going into request internals, like checking req->file->f_op,
do match them based on REQ_F_INFLIGHT, it's set only when we want it to
be reliably cancelled.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
