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This is an already known issue that dm-thin volume cannot be used as
swap, otherwise a deadlock may happen when dm-thin internal memory
demand triggers swap I/O on the dm-thin volume itself.
But thanks to commit a666e5c05e7c ("dm: fix deadlock when swapping to
encrypted device"), the limit_swap_bios target flag can also be used
for dm-thin to avoid the recursive I/O when it is used as swap.
Fix is to simply set ti->limit_swap_bios to true in both pool_ctr()
and thin_ctr().
In my test, I create a dm-thin volume /dev/vg/swap and use it as swap
device. Then I run fio on another dm-thin volume /dev/vg/main and use
large --blocksize to trigger swap I/O onto /dev/vg/swap.
The following fio command line is used in my test,
fio --name recursive-swap-io --lockmem 1 --iodepth 128 \
--ioengine libaio --filename /dev/vg/main --rw randrw \
--blocksize 1M --numjobs 32 --time_based --runtime=12h
Without this fix, the whole system can be locked up within 15 seconds.
With this fix, there is no any deadlock or hung task observed after
2 hours of running fio.
Furthermore, if blocksize is changed from 1M to 128M, after around 30
seconds fio has no visible I/O, and the out-of-memory killer message
shows up in kernel message. After around 20 minutes all fio processes
are killed and the whole system is back to being alive.
This is exactly what is expected when recursive I/O happens on dm-thin
volume when it is used as swap.
Depends-on: a666e5c05e7c ("dm: fix deadlock when swapping to encrypted device")
Cc: stable@vger.kernel.org
Signed-off-by: Coly Li <colyli@suse.de>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Hi Linus,
Please, pull the following patches that transform zero-length arrays,
in unions, into flexible arrays. These patches have been baking in
linux-next for the whole development cycle.
Thanks
--
Gustavo
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Merge tag 'flex-array-transformations-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux
Pull flexible-array updates from Gustavo Silva:
"Transform zero-length arrays, in unions, into flexible arrays"
* tag 'flex-array-transformations-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux:
bcache: Replace zero-length arrays with DECLARE_FLEX_ARRAY() helper
mm/memremap: Replace zero-length array with DECLARE_FLEX_ARRAY() helper
exportfs: Replace zero-length array with DECLARE_FLEX_ARRAY() helper
slab BUG will occur when kmem_cache_destroy() is called.
- Improve 2 of DM's shrinker names to reflect their use.
- Fix the DM flakey target to not corrupt the zero page. Fix dm-flakey
on 32-bit hughmem systems by using bvec_kmap_local instead of
page_address. Also, fix logic used when imposing the
"corrupt_bio_byte" feature.
- Stop using WQ_UNBOUND for DM verity target's verify_wq because it
causes significant Android latencies on ARM64 (and doesn't show real
benefit on other architectures).
- Add negative check to catch simple case of a DM table referencing
itself. More complex scenarios that use intermediate devices to
self-reference still need to be avoided/handled in userspace.
- Fix DM core's resize to only send one uevent instead of two. This
fixes a race with udev, that if udev wins, will cause udev to miss
uevents (which caused premature unmount attempts by systemd).
- Add cond_resched() to workqueue functions in DM core, dn-thin and
dm-cache so that their loops aren't the cause of unintended cpu
scheduling fairness issues.
- Fix all of DM's checkpatch errors and warnings (famous last words).
Various other small cleanups.
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Merge tag 'for-6.3/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull device mapper updates from Mike Snitzer:
- Fix DM cache target to free background tracker work items, otherwise
slab BUG will occur when kmem_cache_destroy() is called.
- Improve 2 of DM's shrinker names to reflect their use.
- Fix the DM flakey target to not corrupt the zero page. Fix dm-flakey
on 32-bit hughmem systems by using bvec_kmap_local instead of
page_address. Also, fix logic used when imposing the
"corrupt_bio_byte" feature.
- Stop using WQ_UNBOUND for DM verity target's verify_wq because it
causes significant Android latencies on ARM64 (and doesn't show real
benefit on other architectures).
- Add negative check to catch simple case of a DM table referencing
itself. More complex scenarios that use intermediate devices to
self-reference still need to be avoided/handled in userspace.
- Fix DM core's resize to only send one uevent instead of two. This
fixes a race with udev, that if udev wins, will cause udev to miss
uevents (which caused premature unmount attempts by systemd).
- Add cond_resched() to workqueue functions in DM core, dn-thin and
dm-cache so that their loops aren't the cause of unintended cpu
scheduling fairness issues.
- Fix all of DM's checkpatch errors and warnings (famous last words).
Various other small cleanups.
* tag 'for-6.3/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (62 commits)
dm: remove unnecessary (void*) conversion in event_callback()
dm ioctl: remove unnecessary check when using dm_get_mdptr()
dm ioctl: assert _hash_lock is held in __hash_remove
dm cache: add cond_resched() to various workqueue loops
dm thin: add cond_resched() to various workqueue loops
dm: add cond_resched() to dm_wq_requeue_work()
dm: add cond_resched() to dm_wq_work()
dm sysfs: make kobj_type structure constant
dm: update targets using system workqueues to use a local workqueue
dm: remove flush_scheduled_work() during local_exit()
dm clone: prefer kvmalloc_array()
dm: declare variables static when sensible
dm: fix suspect indent whitespace
dm ioctl: prefer strscpy() instead of strlcpy()
dm: avoid void function return statements
dm integrity: change macros min/max() -> min_t/max_t where appropriate
dm: fix use of sizeof() macro
dm: avoid 'do {} while(0)' loop in single statement macros
dm log: avoid multiple line dereference
dm log: avoid trailing semicolon in macro
...
API:
- Use kmap_local instead of kmap_atomic.
- Change request callback to take void pointer.
- Print FIPS status in /proc/crypto (when enabled).
Algorithms:
- Add rfc4106/gcm support on arm64.
- Add ARIA AVX2/512 support on x86.
Drivers:
- Add TRNG driver for StarFive SoC.
- Delete ux500/hash driver (subsumed by stm32/hash).
- Add zlib support in qat.
- Add RSA support in aspeed.
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Merge tag 'v6.3-p1' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto update from Herbert Xu:
"API:
- Use kmap_local instead of kmap_atomic
- Change request callback to take void pointer
- Print FIPS status in /proc/crypto (when enabled)
Algorithms:
- Add rfc4106/gcm support on arm64
- Add ARIA AVX2/512 support on x86
Drivers:
- Add TRNG driver for StarFive SoC
- Delete ux500/hash driver (subsumed by stm32/hash)
- Add zlib support in qat
- Add RSA support in aspeed"
* tag 'v6.3-p1' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (156 commits)
crypto: x86/aria-avx - Do not use avx2 instructions
crypto: aspeed - Fix modular aspeed-acry
crypto: hisilicon/qm - fix coding style issues
crypto: hisilicon/qm - update comments to match function
crypto: hisilicon/qm - change function names
crypto: hisilicon/qm - use min() instead of min_t()
crypto: hisilicon/qm - remove some unused defines
crypto: proc - Print fips status
crypto: crypto4xx - Call dma_unmap_page when done
crypto: octeontx2 - Fix objects shared between several modules
crypto: nx - Fix sparse warnings
crypto: ecc - Silence sparse warning
tls: Pass rec instead of aead_req into tls_encrypt_done
crypto: api - Remove completion function scaffolding
tls: Remove completion function scaffolding
tipc: Remove completion function scaffolding
net: ipv6: Remove completion function scaffolding
net: ipv4: Remove completion function scaffolding
net: macsec: Remove completion function scaffolding
dm: Remove completion function scaffolding
...
This pull request contains the following branches:
doc.2023.01.05a: Documentation updates.
fixes.2023.01.23a: Miscellaneous fixes, perhaps most notably:
o Throttling callback invocation based on the number of callbacks
that are now ready to invoke instead of on the total number
of callbacks.
o Several patches that suppress false-positive boot-time
diagnostics, for example, due to lockdep not yet being
initialized.
o Make expedited RCU CPU stall warnings dump stacks of any tasks
that are blocking the stalled grace period. (Normal RCU CPU
stall warnings have doen this for mnay years.)
o Lazy-callback fixes to avoid delays during boot, suspend, and
resume. (Note that lazy callbacks must be explicitly enabled,
so this should not (yet) affect production use cases.)
kvfree.2023.01.03a: Cause kfree_rcu() and friends to take advantage of
polled grace periods, thus reducing memory footprint by almost
two orders of magnitude, admittedly on a microbenchmark.
This series also begins the transition from kfree_rcu(p) to
kfree_rcu_mightsleep(p). This transition was motivated by bugs
where kfree_rcu(p), which can block, was typed instead of the
intended kfree_rcu(p, rh).
srcu.2023.01.03a: SRCU updates, perhaps most notably fixing a bug that
causes SRCU to fail when booted on a system with a non-zero boot
CPU. This surprising situation actually happens for kdump kernels
on the powerpc architecture. It also adds an srcu_down_read()
and srcu_up_read(), which act like srcu_read_lock() and
srcu_read_unlock(), but allow an SRCU read-side critical section
to be handed off from one task to another.
srcu-always.2023.02.02a: Cleans up the now-useless SRCU Kconfig option.
There are a few more commits that are not yet acked or pulled
into maintainer trees, and these will be in a pull request for
a later merge window.
tasks.2023.01.03a: RCU-tasks updates, perhaps most notably these fixes:
o A strange interaction between PID-namespace unshare and the
RCU-tasks grace period that results in a low-probability but
very real hang.
o A race between an RCU tasks rude grace period on a single-CPU
system and CPU-hotplug addition of the second CPU that can result
in a too-short grace period.
o A race between shrinking RCU tasks down to a single callback list
and queuing a new callback to some other CPU, but where that
queuing is delayed for more than an RCU grace period. This can
result in that callback being stranded on the non-boot CPU.
torture.2023.01.05a: Torture-test updates and fixes.
torturescript.2023.01.03a: Torture-test scripting updates and fixes.
stall.2023.01.09a: Provide additional RCU CPU stall-warning information
in kernels built with CONFIG_RCU_CPU_STALL_CPUTIME=y, and
restore the full five-minute timeout limit for expedited RCU
CPU stall warnings.
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Merge tag 'rcu.2023.02.10a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu
Pull RCU updates from Paul McKenney:
- Documentation updates
- Miscellaneous fixes, perhaps most notably:
- Throttling callback invocation based on the number of callbacks
that are now ready to invoke instead of on the total number of
callbacks
- Several patches that suppress false-positive boot-time
diagnostics, for example, due to lockdep not yet being
initialized
- Make expedited RCU CPU stall warnings dump stacks of any tasks
that are blocking the stalled grace period. (Normal RCU CPU
stall warnings have done this for many years)
- Lazy-callback fixes to avoid delays during boot, suspend, and
resume. (Note that lazy callbacks must be explicitly enabled, so
this should not (yet) affect production use cases)
- Make kfree_rcu() and friends take advantage of polled grace periods,
thus reducing memory footprint by almost two orders of magnitude,
admittedly on a microbenchmark
This also begins the transition from kfree_rcu(p) to
kfree_rcu_mightsleep(p). This transition was motivated by bugs where
kfree_rcu(p), which can block, was typed instead of the intended
kfree_rcu(p, rh)
- SRCU updates, perhaps most notably fixing a bug that causes SRCU to
fail when booted on a system with a non-zero boot CPU. This
surprising situation actually happens for kdump kernels on the
powerpc architecture
This also adds an srcu_down_read() and srcu_up_read(), which act like
srcu_read_lock() and srcu_read_unlock(), but allow an SRCU read-side
critical section to be handed off from one task to another
- Clean up the now-useless SRCU Kconfig option
There are a few more commits that are not yet acked or pulled into
maintainer trees, and these will be in a pull request for a later
merge window
- RCU-tasks updates, perhaps most notably these fixes:
- A strange interaction between PID-namespace unshare and the
RCU-tasks grace period that results in a low-probability but
very real hang
- A race between an RCU tasks rude grace period on a single-CPU
system and CPU-hotplug addition of the second CPU that can
result in a too-short grace period
- A race between shrinking RCU tasks down to a single callback
list and queuing a new callback to some other CPU, but where
that queuing is delayed for more than an RCU grace period. This
can result in that callback being stranded on the non-boot CPU
- Torture-test updates and fixes
- Torture-test scripting updates and fixes
- Provide additional RCU CPU stall-warning information in kernels built
with CONFIG_RCU_CPU_STALL_CPUTIME=y, and restore the full five-minute
timeout limit for expedited RCU CPU stall warnings
* tag 'rcu.2023.02.10a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (80 commits)
rcu/kvfree: Add kvfree_rcu_mightsleep() and kfree_rcu_mightsleep()
kernel/notifier: Remove CONFIG_SRCU
init: Remove "select SRCU"
fs/quota: Remove "select SRCU"
fs/notify: Remove "select SRCU"
fs/btrfs: Remove "select SRCU"
fs: Remove CONFIG_SRCU
drivers/pci/controller: Remove "select SRCU"
drivers/net: Remove "select SRCU"
drivers/md: Remove "select SRCU"
drivers/hwtracing/stm: Remove "select SRCU"
drivers/dax: Remove "select SRCU"
drivers/base: Remove CONFIG_SRCU
rcu: Disable laziness if lazy-tracking says so
rcu: Track laziness during boot and suspend
rcu: Remove redundant call to rcu_boost_kthread_setaffinity()
rcu: Allow up to five minutes expedited RCU CPU stall-warning timeouts
rcu: Align the output of RCU CPU stall warning messages
rcu: Add RCU stall diagnosis information
sched: Add helper nr_context_switches_cpu()
...
Pointer variables of void * type do not require type cast.
Signed-off-by: XU pengfei <xupengfei@nfschina.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
__hash_remove() removes hash_cell with _hash_lock locked, so acquiring
_hash_lock can guarantee no-NULL hc returned from dm_get_mdptr() must
have not been removed and hc->md must still be md.
__hash_remove() also acquires dm_hash_cells_mutex before setting mdptr
as NULL. So in dm_copy_name_and_uuid(), after acquiring
dm_hash_cells_mutex and ensuring returned hc is not NULL, the returned
hc must still be alive and hc->md must still be md.
Remove the unnecessary hc->md != md checks when using dm_get_mdptr()
with _hash_lock or dm_hash_cells_mutex acquired.
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Also update dm_early_create() to take _hash_lock when calling both
__get_name_cell and __hash_remove -- given dm_early_create()'s early
boot usecase this locking isn't about correctness but it allows
lockdep_assert_held() to be added to __hash_remove.
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Otherwise the while() loop in dm_wq_requeue_work() can result in a
"dead loop" on systems that have preemption disabled. This is
particularly problematic on single cpu systems.
Fixes: 8b211aaccb915 ("dm: add two stage requeue mechanism")
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Otherwise the while() loop in dm_wq_work() can result in a "dead
loop" on systems that have preemption disabled. This is particularly
problematic on single cpu systems.
Cc: stable@vger.kernel.org
Signed-off-by: Pingfan Liu <piliu@redhat.com>
Acked-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Since commit ee6d3dd4ed48 ("driver core: make kobj_type constant.")
the driver core allows the usage of const struct kobj_type.
Take advantage of this to constify the structure definition to prevent
modification at runtime.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Flushing system-wide workqueues is dangerous and will be forbidden.
Use a local workqueue in dm-mpath.c, dm-raid1.c, and dm-stripe.c.
Link: https://lkml.kernel.org/r/49925af7-78a8-a3dd-bce6-cfc02e1a9236@I-love.SAKURA.ne.jp
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Commit acfe0ad74d2e1 ("dm: allocate a special workqueue for deferred
device removal") switched from using system workqueue to a single
workqueue local to DM. But it didn't eliminate the call to
flush_scheduled_work() that was introduced purely for the benefit of
deferred device removal with commit 2c140a246dc ("dm: allow remove to
be deferred").
Since DM core uses its own workqueue (and queue_work) there is no need
to call flush_scheduled_work() from local_exit(). local_exit()'s
destroy_workqueue(deferred_remove_workqueue) handles flushing work
started with queue_work().
Fixes: acfe0ad74d2e1 ("dm: allocate a special workqueue for deferred device removal")
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
