blk-iocost: use irq-safe locking in cgroup handlers#913
Open
blktests-ci[bot] wants to merge 1 commit into
Open
blk-iocost: use irq-safe locking in cgroup handlers#913blktests-ci[bot] wants to merge 1 commit into
blktests-ci[bot] wants to merge 1 commit into
Conversation
Author
|
Upstream branch: 8fde5d1 |
blktests-ci
Bot
force-pushed
the
linus-master_base
branch
from
3f4a345 to
c6dc343
Compare
Author
|
Upstream branch: e43ffb6 |
blktests-ci
Bot
force-pushed
the
series/1103769=>linus-master
branch
from
6c0c7d1 to
44fd214
Compare
blktests-ci
Bot
force-pushed
the
linus-master_base
branch
from
c6dc343 to
fc36596
Compare
Author
|
Upstream branch: ba3e43a |
blktests-ci
Bot
force-pushed
the
series/1103769=>linus-master
branch
from
44fd214 to
93bc5e8
Compare
blktests-ci
Bot
force-pushed
the
linus-master_base
branch
from
fc36596 to
7bed9c3
Compare
Author
|
Upstream branch: ddd664b |
blktests-ci
Bot
force-pushed
the
series/1103769=>linus-master
branch
from
93bc5e8 to
34737a5
Compare
blktests-ci
Bot
force-pushed
the
linus-master_base
branch
from
7bed9c3 to
a7bb5c5
Compare
Author
|
Upstream branch: 979c294 |
blktests-ci
Bot
force-pushed
the
series/1103769=>linus-master
branch
from
34737a5 to
38f0e00
Compare
blktests-ci
Bot
force-pushed
the
linus-master_base
branch
from
a7bb5c5 to
5e41a3b
Compare
Author
|
Upstream branch: acb7500 |
blktests-ci
Bot
force-pushed
the
series/1103769=>linus-master
branch
from
38f0e00 to
26761c2
Compare
blktests-ci
Bot
force-pushed
the
linus-master_base
branch
from
5e41a3b to
c3a084b
Compare
Author
|
Upstream branch: 9716c08 |
blktests-ci
Bot
force-pushed
the
series/1103769=>linus-master
branch
from
26761c2 to
5baea94
Compare
blktests-ci
Bot
force-pushed
the
linus-master_base
branch
from
c3a084b to
5f78e5d
Compare
Author
|
Upstream branch: 2a2974b |
blktests-ci
Bot
force-pushed
the
series/1103769=>linus-master
branch
from
5baea94 to
1ea88e0
Compare
blktests-ci
Bot
force-pushed
the
linus-master_base
branch
from
5f78e5d to
e48f9db
Compare
Author
|
Upstream branch: 062871f |
blktests-ci
Bot
force-pushed
the
series/1103769=>linus-master
branch
from
1ea88e0 to
83e7558
Compare
blktests-ci
Bot
force-pushed
the
linus-master_base
branch
2 times, most recently
from
199644a to
e6d9eb8
Compare
Author
|
Upstream branch: 66affa3 |
blktests-ci
Bot
force-pushed
the
series/1103769=>linus-master
branch
from
83e7558 to
ec1ea0b
Compare
blktests-ci
Bot
force-pushed
the
linus-master_base
branch
from
e6d9eb8 to
7d8604f
Compare
ioc_timer_fn() acquires ioc->lock from timer softirq context. The io.weight, io.cost.qos and io.cost.model cgroup handlers can take the same lock from process context, and the direct handler paths must not do so with interrupts enabled. A blkcg policy configuration reproducer with lockdep reproduced the following report: WARNING: inconsistent lock state 7.1.0-rc2-g1e14adca0199 #1 Not tainted -------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. swapper/2/0 [HC0[0]:SC1[1]:HE0:SE0] takes: ffff88810f95d0f8 (&ioc->lock){+.?.}-{3:3}, at: ioc_timer_fn+0x3ff/0x3af0 {SOFTIRQ-ON-W} state was registered at: lock_acquire+0xd4/0x290 _raw_spin_lock+0x3a/0x70 ioc_weight_write+0x35a/0x420 cgroup_file_write+0x1c5/0x4b0 kernfs_fop_write_iter+0x1d7/0x280 vfs_write+0x580/0x630 ksys_write+0xec/0x190 do_syscall_64+0x156/0x490 entry_SYSCALL_64_after_hwframe+0x77/0x7f Possible unsafe locking scenario: CPU0 ---- lock(&ioc->lock); <Interrupt> lock(&ioc->lock); *** DEADLOCK *** 1 lock held by swapper/2/0: #0: ffffc90000230d20 ((&ioc->timer)){+.-.}-{0:0}, at: call_timer_fn+0xba/0x3a0 stack backtrace: CPU: 2 UID: 0 PID: 0 Comm: swapper/2 Not tainted 7.1.0-rc2-g1e14adca0199 #1 PREEMPT ea13f83d4b74a12510d20db4a7d9a0fe8275f05c Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-5.fc42 04/01/2014 Call Trace: <IRQ> dump_stack_lvl+0x54/0x70 print_usage_bug+0x26d/0x280 mark_lock_irq+0x3ef/0x400 mark_lock+0x117/0x190 __lock_acquire+0x592/0x2850 lock_acquire+0xd4/0x290 _raw_spin_lock_irq+0x49/0x80 ioc_timer_fn+0x3ff/0x3af0 call_timer_fn+0x120/0x3a0 __run_timer_base+0x3ad/0x490 run_timer_softirq+0x31/0x60 handle_softirqs+0x1a0/0x550 __irq_exit_rcu+0x8c/0x150 irq_exit_rcu+0xe/0x20 sysvec_apic_timer_interrupt+0x6e/0x80 </IRQ> Use spin_lock_irq() in the affected process-context handlers. The default io.weight update already holds blkcg->lock with spin_lock_irq(), so the nested ioc->lock acquisition there is already IRQ-safe and is left as a plain spin_lock(). Fixes: 7caa471 ("blkcg: implement blk-iocost") Signed-off-by: Yu Kuai <yukuai@fygo.io>
Author
|
Upstream branch: bade58e |
blktests-ci
Bot
force-pushed
the
series/1103769=>linus-master
branch
from
ec1ea0b to
edbd2d3
Compare
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Pull request for series with
subject: blk-iocost: use irq-safe locking in cgroup handlers
version: 1
url: https://patchwork.kernel.org/project/linux-block/list/?series=1103769