Open-iSCSI sends passthrough PDUs over netlink, but the kernel should be
verifying that the provided PDU header and data lengths fall within the
netlink message to prevent accessing beyond that in memory.
Cc: stable@vger.kernel.org
Reported-by: Adam Nichols <adam@grimm-co.com>
Reviewed-by: Lee Duncan <lduncan@suse.com>
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Chris Leech <cleech@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
As the iSCSI parameters are exported back through sysfs, it should be
enforcing that they never are more than PAGE_SIZE (which should be more
than enough) before accepting updates through netlink.
Change all iSCSI sysfs attributes to use sysfs_emit().
Cc: stable@vger.kernel.org
Reported-by: Adam Nichols <adam@grimm-co.com>
Reviewed-by: Lee Duncan <lduncan@suse.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Chris Leech <cleech@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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>
Optional Forward Error Correction (FEC) code in dm-verity uses
Reed-Solomon code and should support roots from 2 to 24.
The error correction parity bytes (of roots lengths per RS block) are
stored on a separate device in sequence without any padding.
Currently, to access FEC device, the dm-verity-fec code uses dm-bufio
client with block size set to verity data block (usually 4096 or 512
bytes).
Because this block size is not divisible by some (most!) of the roots
supported lengths, data repair cannot work for partially stored parity
bytes.
This fix changes FEC device dm-bufio block size to "roots << SECTOR_SHIFT"
where we can be sure that the full parity data is always available.
(There cannot be partial FEC blocks because parity must cover whole
sectors.)
Because the optional FEC starting offset could be unaligned to this
new block size, we have to use dm_bufio_set_sector_offset() to
configure it.
The problem is easily reproduced using veritysetup, e.g. for roots=13:
# create verity device with RS FEC
dd if=/dev/urandom of=data.img bs=4096 count=8 status=none
veritysetup format data.img hash.img --fec-device=fec.img --fec-roots=13 | awk '/^Root hash/{ print $3 }' >roothash
# create an erasure that should be always repairable with this roots setting
dd if=/dev/zero of=data.img conv=notrunc bs=1 count=8 seek=4088 status=none
# try to read it through dm-verity
veritysetup open data.img test hash.img --fec-device=fec.img --fec-roots=13 $(cat roothash)
dd if=/dev/mapper/test of=/dev/null bs=4096 status=noxfer
# wait for possible recursive recovery in kernel
udevadm settle
veritysetup close test
With this fix, errors are properly repaired.
device-mapper: verity-fec: 7:1: FEC 0: corrected 8 errors
...
Without it, FEC code usually ends on unrecoverable failure in RS decoder:
device-mapper: verity-fec: 7:1: FEC 0: failed to correct: -74
...
This problem is present in all kernels since the FEC code's
introduction (kernel 4.5).
It is thought that this problem is not visible in Android ecosystem
because it always uses a default RS roots=2.
Depends-on: a14e5ec66a ("dm bufio: subtract the number of initial sectors in dm_bufio_get_device_size")
Signed-off-by: Milan Broz <gmazyland@gmail.com>
Tested-by: Jérôme Carretero <cJ-ko@zougloub.eu>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Cc: stable@vger.kernel.org # 4.5+
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
dm_bufio_get_device_size returns the device size in blocks. Before
returning the value, we must subtract the nubmer of starting
sectors. The number of starting sectors may not be divisible by block
size.
Note that currently, no target is using dm_bufio_set_sector_offset and
dm_bufio_get_device_size simultaneously, so this change has no effect.
However, an upcoming dm-verity-fec fix needs this change.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Milan Broz <gmazyland@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* selftests fixes
* Add runstate information to the new Xen support
* Allow compiling out the Xen interface
* 32-bit PAE without EPT bugfix
* NULL pointer dereference bugfix
-----BEGIN PGP SIGNATURE-----
iQFIBAABCAAyFiEE8TM4V0tmI4mGbHaCv/vSX3jHroMFAmA+lGcUHHBib256aW5p
QHJlZGhhdC5jb20ACgkQv/vSX3jHroMaMQf/Q8bQr5vVAeNk+1MyRmzNqFEbLqbe
h50f4Wd2N+svZ6XinQH1vvuQm1WYj/g616Q3nCeYwCJyY34g5tf60XcuAMnVRIzw
qc2IUvSAJ3faVElMrSA5thN3bkPzJpRrdIpQGBgOd+rT+eQkPSsJlTy34JJmvbmh
xFGjoVj49tYEkFfpxEbtytW6QiYtPz/ai8SARRXbEUWO/pVzdkgK5XWshRhE9vpB
GLCEXUngdPokJMblRMuK4YOSFQXXHobAJAgPwSzguDV41qezXaKOGYOLe7+V+0kH
z607RnQc1wGgsLanT13okYMQr09/XCjpvFkZ9CK2bIJPsyWP+ihA/37hVQ==
=1GNo
-----END PGP SIGNATURE-----
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Paolo Bonzini:
- Doc fixes
- selftests fixes
- Add runstate information to the new Xen support
- Allow compiling out the Xen interface
- 32-bit PAE without EPT bugfix
- NULL pointer dereference bugfix
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: SVM: Clear the CR4 register on reset
KVM: x86/xen: Add support for vCPU runstate information
KVM: x86/xen: Fix return code when clearing vcpu_info and vcpu_time_info
selftests: kvm: Mmap the entire vcpu mmap area
KVM: Documentation: Fix index for KVM_CAP_PPC_DAWR1
KVM: x86: allow compiling out the Xen hypercall interface
KVM: xen: flush deferred static key before checking it
KVM: x86/mmu: Set SPTE_AD_WRPROT_ONLY_MASK if and only if PML is enabled
KVM: x86: hyper-v: Fix Hyper-V context null-ptr-deref
KVM: x86: remove misplaced comment on active_mmu_pages
KVM: Documentation: rectify rst markup in kvm_run->flags
Documentation: kvm: fix messy conversion from .txt to .rst
-----BEGIN PGP SIGNATURE-----
iHUEABYIAB0WIQRTLbB6QfY48x44uB6AXGG7T9hjvgUCYEC9gwAKCRCAXGG7T9hj
vswYAP0V7gIfsbKMONeHJtmIJlVT0igtFMRMKrHL4TqEnv3mgQEAglhC+fNMmqdP
WJOMxMZvkfQYhNMaodwpTlFMhnFW8As=
=NiJF
-----END PGP SIGNATURE-----
Merge tag 'for-linus-5.12b-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen fixes from Juergen Gross:
"Two security issues (XSA-367 and XSA-369)"
* tag 'for-linus-5.12b-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen: fix p2m size in dom0 for disabled memory hotplug case
xen-netback: respect gnttab_map_refs()'s return value
Xen/gnttab: handle p2m update errors on a per-slot basis
Slightly bulky changes are seen at this time, mostly for dealing
with the messed up Kconfig for ASoC Intel SOF stuff. The driver
and its code was split to each module per platform now, which is
far more straightforward. This should cover the randconfig
problems, and more importantly, improve the actual device handling
as well.
Other than that, nothing particular stands out: the HDMI PCM
assignment fix for Intel Tigerlake, MIPS n64 error handling fix,
and the usual suspects, HD-audio / USB-audio quirks.
-----BEGIN PGP SIGNATURE-----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=FOED
-----END PGP SIGNATURE-----
Merge tag 'sound-5.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
Pull sound fixes from Takashi Iwai:
"Slightly bulky changes are seen at this time, mostly for dealing with
the messed up Kconfig for ASoC Intel SOF stuff. The driver and its
code was split to each module per platform now, which is far more
straightforward. This should cover the randconfig problems, and more
importantly, improve the actual device handling as well.
Other than that, nothing particular stands out: the HDMI PCM
assignment fix for Intel Tigerlake, MIPS n64 error handling fix, and
the usual suspects, HD-audio / USB-audio quirks"
* tag 'sound-5.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (21 commits)
ALSA: hda/realtek: Apply dual codec quirks for MSI Godlike X570 board
ALSA: hda/realtek: Add quirk for Intel NUC 10
ALSA: hda/hdmi: let new platforms assign the pcm slot dynamically
ALSA: hda/realtek: Add quirk for Clevo NH55RZQ
ALSA: hda: intel-sdw-acpi: add missing include files
ALSA: hda: move Intel SoundWire ACPI scan to dedicated module
ASoC: SOF: Intel: SoundWire: simplify Kconfig
ASoC: SOF: pci: move DSP_CONFIG use to platform-specific drivers
ASoC: SOF: pci: split PCI into different drivers
ASoC: SOF: ACPI: avoid reverse module dependency
ASoC: soc-acpi: allow for partial match in parent name
ALSA: hda: intel-nhlt: verify config type
ALSA: hda: fix kernel-doc warnings
ALSA: usb-audio: Fix Pioneer DJM devices URB_CONTROL request direction to set samplerate
ALSA: usb-audio: use Corsair Virtuoso mapping for Corsair Virtuoso SE
ALSA: hda/realtek: Enable headset mic of Acer SWIFT with ALC256
ALSA: ctxfi: cthw20k2: fix mask on conf to allow 4 bits
ALSA: usb-audio: Allow modifying parameters with succeeding hw_params calls
ALSA: usb-audio: Drop bogus dB range in too low level
ALSA: usb-audio: Don't abort even if the clock rate differs
...
We migrate zone unusable bytes to read-only bytes when a block group is
set to read-only, and account all the free region as bytes_readonly.
Thus, we should not increase block_group->zone_unusable when the block
group is read-only.
Fixes: 169e0da91a ("btrfs: zoned: track unusable bytes for zones")
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We need to use sector_t for zone_sectors, or it would set the zone size
to zero when the size >= 4GB (= 2^24 sectors) by shifting the
zone_sectors value by SECTOR_SHIFT. We're assuming zones sizes up to
8GiB.
Fixes: 5b31646898 ("btrfs: get zone information of zoned block devices")
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In the declaration of the struct trace_event_call, the flags has the bits
defined in the comment above it. But these bits are also defined by the
TRACE_EVENT_FL_* enums just above the declaration of the struct. As the
comment about the flags in the struct has become stale and incorrect, just
replace it with a reference to the TRACE_EVENT_FL_* enum above.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
If tracing is disabled for some reason (traceoff_on_warning, command line,
etc), the ftrace selftests are guaranteed to fail, as their results are
defined by trace data in the ring buffers. If the ring buffers are turned
off, the tests will fail, due to lack of data.
Because tracing being disabled is for a specific reason (warning, user
decided to, etc), it does not make sense to enable tracing to run the self
tests, as the test output may corrupt the reason for the tracing to be
disabled.
Instead, simply skip the self tests and report that they are being skipped
due to tracing being disabled.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
When the CONFIG_RING_BUFFER_VALIDATE_TIME_DELTAS is enabled, and the time
stamps are detected as not being valid, it reports information about the
write stamp, but does not show the before_stamp which is still useful
information. Also, it should give a warning once, such that tests detect
this happening.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Part of the logic of the new time stamp code depends on the before_stamp and
the write_stamp to be different if the write_stamp does not match the last
event on the buffer, as it will be used to calculate the delta of the next
event written on the buffer.
The discard logic depends on this, as the next event to come in needs to
inject a full timestamp as it can not rely on the last event timestamp in
the buffer because it is unknown due to events after it being discarded. But
by changing the write_stamp back to the time before it, it forces the next
event to use a full time stamp, instead of relying on it.
The issue came when a full time stamp was used for the event, and
rb_time_delta() returns zero in that case. The update to the write_stamp
(which subtracts delta) made it not change. Then when the event is removed
from the buffer, because the before_stamp and write_stamp still match, the
next event written would calculate its delta from the write_stamp, but that
would be wrong as the write_stamp is of the time of the event that was
discarded.
In the case that the delta change being made to write_stamp is zero, set the
before_stamp to zero as well, and this will force the next event to inject a
full timestamp and not use the current write_stamp.
Cc: stable@vger.kernel.org
Fixes: a389d86f7f ("ring-buffer: Have nested events still record running time stamp")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
A declaration of function "int trace_empty(struct trace_iterator *iter)"
shows up twice in the header file kernel/trace/trace.h
Link: https://lkml.kernel.org/r/20210304092348.208033-1-y.karadz@gmail.com
Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
If we race on shutting down the io-wq, then we should ensure that any
work that was queued after workers shutdown is canceled. Harden the
add work check a bit too, checking for IO_WQ_BIT_EXIT and cancel if
it's set.
Add a WARN_ON() for having any work before we kill the io-wq context.
Reported-by: syzbot+91b4b56ead187d35c9d3@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
io_dismantle_req() is always followed by io_put_task(), which already do
proper in_idle wake ups, so we can skip waking the owner task in
io_dismantle_req(). The rules are simpler now, do io_put_task() shortly
after ending a request, and it will be fine.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
__io_queue_async_work() is only called from io_queue_async_work(),
inline it.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Inline io_req_clean_work(), less code and easier to analyse
tctx dependencies and refs usage.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When we cancel SQPOLL, @task in io_uring_try_cancel_requests() will
differ from current. Use the right tctx from passed in @task, and don't
forget that it can be NULL when the io_uring ctx exits.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We no longer revert the iovec on -EIOCBQUEUED, see commit ab2125df92,
and this started causing issues for IOPOLL on devies that run out of
request slots. Turns out what outside of needing a revert for those, we
also had a bug where we didn't properly setup retry inside the submission
path. That could cause re-import of the iovec, if any, and that could lead
to spurious results if the application had those allocated on the stack.
Catch -EAGAIN retry and make the iovec stable for IOPOLL, just like we do
for !IOPOLL retries.
Cc: <stable@vger.kernel.org> # 5.9+
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Reported-by: Xiaoguang Wang <xiaoguang.wang@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The 'err' path should include the hash put, we already grabbed a reference
once we get that far.
Fixes: e941894eae ("io-wq: make buffered file write hashed work map per-ctx")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Now, sqo_task is used only for a warning that is not interesting anymore
since sqo_dead is gone, remove all of that including ctx->sqo_task.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
As SQPOLL task doesn't poke into ->sqo_task anymore, there is no need to
kill the sqo when the master task exits. Before it was necessary to
avoid races accessing sqo_task->files with removing them.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
[axboe: don't forget to enable SQPOLL before exit, if started disabled]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
If we create it in a disabled state because IORING_SETUP_R_DISABLED is
set on ring creation, we need to ensure that we've kicked the thread if
we're exiting before it's been explicitly disabled. Otherwise we can run
into a deadlock where exit is waiting go park the SQPOLL thread, but the
SQPOLL thread itself is waiting to get a signal to start.
That results in the below trace of both tasks hung, waiting on each other:
INFO: task syz-executor458:8401 blocked for more than 143 seconds.
Not tainted 5.11.0-next-20210226-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor458 state:D stack:27536 pid: 8401 ppid: 8400 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:4324 [inline]
__schedule+0x90c/0x21a0 kernel/sched/core.c:5075
schedule+0xcf/0x270 kernel/sched/core.c:5154
schedule_timeout+0x1db/0x250 kernel/time/timer.c:1868
do_wait_for_common kernel/sched/completion.c:85 [inline]
__wait_for_common kernel/sched/completion.c:106 [inline]
wait_for_common kernel/sched/completion.c:117 [inline]
wait_for_completion+0x168/0x270 kernel/sched/completion.c:138
io_sq_thread_park fs/io_uring.c:7115 [inline]
io_sq_thread_park+0xd5/0x130 fs/io_uring.c:7103
io_uring_cancel_task_requests+0x24c/0xd90 fs/io_uring.c:8745
__io_uring_files_cancel+0x110/0x230 fs/io_uring.c:8840
io_uring_files_cancel include/linux/io_uring.h:47 [inline]
do_exit+0x299/0x2a60 kernel/exit.c:780
do_group_exit+0x125/0x310 kernel/exit.c:922
__do_sys_exit_group kernel/exit.c:933 [inline]
__se_sys_exit_group kernel/exit.c:931 [inline]
__x64_sys_exit_group+0x3a/0x50 kernel/exit.c:931
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x43e899
RSP: 002b:00007ffe89376d48 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00000000004af2f0 RCX: 000000000043e899
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffffffffffc0 R09: 0000000010000000
R10: 0000000000008011 R11: 0000000000000246 R12: 00000000004af2f0
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001
INFO: task iou-sqp-8401:8402 can't die for more than 143 seconds.
task:iou-sqp-8401 state:D stack:30272 pid: 8402 ppid: 8400 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:4324 [inline]
__schedule+0x90c/0x21a0 kernel/sched/core.c:5075
schedule+0xcf/0x270 kernel/sched/core.c:5154
schedule_timeout+0x1db/0x250 kernel/time/timer.c:1868
do_wait_for_common kernel/sched/completion.c:85 [inline]
__wait_for_common kernel/sched/completion.c:106 [inline]
wait_for_common kernel/sched/completion.c:117 [inline]
wait_for_completion+0x168/0x270 kernel/sched/completion.c:138
io_sq_thread+0x27d/0x1ae0 fs/io_uring.c:6717
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
INFO: task iou-sqp-8401:8402 blocked for more than 143 seconds.
Reported-by: syzbot+fb5458330b4442f2090d@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
io_run_ctx_fallback() can use xchg() instead of cmpxchg(). It's simpler
and faster.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
There is an unlikely but possible race using a freed context. That's
because req->task_work.func() can free a request, but we won't
necessarily find a completion in submit_state.comp and so all ctx refs
may be put by the time we do mutex_lock(&ctx->uring_ctx);
There are several reasons why it can miss going through
submit_state.comp: 1) req->task_work.func() didn't complete it itself,
but punted to iowq (e.g. reissue) and it got freed later, or a similar
situation with it overflowing and getting flushed by someone else, or
being submitted to IRQ completion, 2) As we don't hold the uring_lock,
someone else can do io_submit_flush_completions() and put our ref.
3) Bugs and code obscurities, e.g. failing to propagate issue_flags
properly.
One example is as follows
CPU1 | CPU2
=======================================================================
@req->task_work.func() |
-> @req overflwed, |
so submit_state.comp,nr==0 |
| flush overflows, and free @req
| ctx refs == 0, free it
ctx is dead, but we do |
lock + flush + unlock |
So take a ctx reference for each new ctx we see in __tctx_task_work(),
and do release it until we do all our flushing.
Fixes: 65453d1efb ("io_uring: enable req cache for task_work items")
Reported-by: syzbot+a157ac7c03a56397f553@syzkaller.appspotmail.com
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
[axboe: fold in my one-liner and fix ref mismatch]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We already run the fallback task_work in io_uring_try_cancel_requests(),
no need to duplicate at ring exit explicitly.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
If we move it in there, then we no longer have to care about it in io-wq.
This means we can drop the cred handling in io-wq, and we can drop the
REQ_F_WORK_INITIALIZED flag and async init functions as that was the last
user of it since we moved to the new workers. Then we can also drop
io_wq_work->creds, and just hold the personality u16 in there instead.
Suggested-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We're no longer checking anything that requires the work item to be
initialized, as we're not carrying any file related state there.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Destroy current's io-wq backend and tctx on __io_uring_task_cancel(),
aka exec(). Looks it's not strictly necessary, because it will be done
at some point when the task dies and changes of creds/files/etc. are
handled, but better to do that earlier to free io-wq and not potentially
lock previous mm and other resources for the time being.
It's safe to do because we wait for all requests of the current task to
complete, so no request will use tctx afterwards. Note, that
io_uring_files_cancel() may leave some requests for later reaping, so it
leaves tctx intact, that's ok as the task is dying anyway.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Make sure that we killed an io-wq by the time a task is dead.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We clear the bit marking the ctx task_work as active after having run
the queued work, but we really should be clearing it before. Otherwise
we can hit a tiny race ala:
CPU0 CPU1
io_task_work_add() tctx_task_work()
run_work
add_to_list
test_and_set_bit
clear_bit
already set
and CPU0 will return thinking the task_work is queued, while in reality
it's already being run. If we hit the condition after __tctx_task_work()
found no more work, but before we've cleared the bit, then we'll end up
thinking it's queued and will be run. In reality it is queued, but we
didn't queue the ctx task_work to ensure that it gets run.
Fixes: 7cbf1722d5 ("io_uring: provide FIFO ordering for task_work")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
If we put the io-wq from io_uring, we really want it to exit. Provide
a helper that does that for us. Couple that with not having the manager
hold a reference to the 'wq' and the normal SQPOLL exit will tear down
the io-wq context appropriate.
On the io-wq side, our wq context is per task, so only the task itself
is manipulating ->manager and hence it's safe to check and clear without
any extra locking. We just need to ensure that the manager task stays
around, in case it exits.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We want to reuse this completion, and a single complete should do just
fine. Ensure that we park ourselves first if requested, as that is what
lead to the initial deadlock in this area. If we've got someone attempting
to park us, then we can't proceed without having them finish first.
Fixes: 37d1e2e364 ("io_uring: move SQPOLL thread io-wq forked worker")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
io_uring_try_cancel_requests() matches not only current's requests, but
also of other exiting tasks, so we need to actively cancel them and not
just wait, especially since the function can be called on flush during
do_exit() -> exit_files().
Even if it's not a problem for now, it's much nicer to know that the
function tries to cancel everything it can.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
If we fail to fork an SQPOLL worker, we can hit cancel, and hence
attempted thread stop, with the thread already being stopped. Ensure
we check for that.
Also guard thread stop fully by the sqd mutex, just like we do for
park.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We are already freeing the wq struct in both spots, so don't put it and
get it freed twice.
Reported-by: syzbot+7bf785eedca35ca05501@syzkaller.appspotmail.com
Fixes: 4fb6ac3262 ("io-wq: improve manager/worker handling over exec")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The manager waits for the workers, hence the manager is always valid if
workers are running. Now also have wq destroy wait for the manager on
exit, so we now everything is gone.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This is a leftover from a different use cases, it's used to wait for
the manager to startup. Rename it as such.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
