linux/io_uring/timeout.c, branch v6.15

Merge tag 'for-6.15/io_uring-20250322' of git://git.kernel.dk/linux

2025-03-27T00:56:00Z

Pull io_uring updates from Jens Axboe: "This is the first of the io_uring pull requests for the 6.15 merge window, there will be others once the net tree has gone in. This contains: - Cleanup and unification of cancelation handling across various request types. - Improvement for bundles, supporting them both for incrementally consumed buffers, and for non-multishot requests. - Enable toggling of using iowait while waiting on io_uring events or not. Unfortunately this is still tied with CPU frequency boosting on short waits, as the scheduler side has not been very receptive to splitting the (useless) iowait stat from the cpufreq implied boost. - Add support for kbuf nodes, enabling zero-copy support for the ublk block driver. - Various cleanups for resource node handling. - Series greatly cleaning up the legacy provided (non-ring based) buffers. For years, we've been pushing the ring provided buffers as the way to go, and that is what people have been using. Reduce the complexity and code associated with legacy provided buffers. - Series cleaning up the compat handling. - Series improving and cleaning up the recvmsg/sendmsg iovec and msg handling. - Series of cleanups for io-wq. - Start adding a bunch of selftests. The liburing repository generally carries feature and regression tests for everything, but at least for ublk initially, we'll try and go the route of having it in selftests as well. We'll see how this goes, might decide to migrate more tests this way in the future. - Various little cleanups and fixes" * tag 'for-6.15/io_uring-20250322' of git://git.kernel.dk/linux: (108 commits) selftests: ublk: add stripe target selftests: ublk: simplify loop io completion selftests: ublk: enable zero copy for null target selftests: ublk: prepare for supporting stripe target selftests: ublk: move common code into common.c selftests: ublk: increase max buffer size to 1MB selftests: ublk: add single sqe allocator helper selftests: ublk: add generic_01 for verifying sequential IO order selftests: ublk: fix starting ublk device io_uring: enable toggle of iowait usage when waiting on CQEs selftests: ublk: fix write cache implementation selftests: ublk: add variable for user to not show test result selftests: ublk: don't show `modprobe` failure selftests: ublk: add one dependency header io_uring/kbuf: enable bundles for incrementally consumed buffers Revert "io_uring/rsrc: simplify the bvec iter count calculation" selftests: ublk: improve test usability selftests: ublk: add stress test for covering IO vs. killing ublk server selftests: ublk: add one stress test for covering IO vs. removing device selftests: ublk: load/unload ublk_drv when preparing & cleaning up tests ...

io_uring/timeout: Switch to use hrtimer_setup()

2025-02-18T09:32:32Z

hrtimer_setup() takes the callback function pointer as argument and initializes the timer completely. Replace hrtimer_init() and the open coded initialization of hrtimer::function with the new setup mechanism. Signed-off-by: Nam Cao Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/80ca8d959f2cc67c75f6d61008e3bebfe7fbc30a.1738746821.git.namcao@linutronix.de

io_uring: introduce type alias for io_tw_state

2025-02-17T12:34:50Z

In preparation for changing how io_tw_state is passed, introduce a type alias io_tw_token_t for struct io_tw_state *. This allows for changing the representation in one place, without having to update the many functions that just forward their struct io_tw_state * argument. Also add a comment to struct io_tw_state to explain its purpose. Signed-off-by: Caleb Sander Mateos Link: https://lore.kernel.org/r/20250217022511.1150145-1-csander@purestorage.com Signed-off-by: Jens Axboe

io_uring/alloc_cache: get rid of _nocache() helper

2025-01-23T18:32:34Z

Just allow passing in NULL for the cache, if the type in question doesn't have a cache associated with it. Signed-off-by: Jens Axboe

Merge tag 'for-6.14/io_uring-20250119' of git://git.kernel.dk/linux

2025-01-21T04:27:33Z

Pull io_uring updates from Jens Axboe: "Not a lot in terms of features this time around, mostly just cleanups and code consolidation: - Support for PI meta data read/write via io_uring, with NVMe and SCSI covered - Cleanup the per-op structure caching, making it consistent across various command types - Consolidate the various user mapped features into a concept called regions, making the various users of that consistent - Various cleanups and fixes" * tag 'for-6.14/io_uring-20250119' of git://git.kernel.dk/linux: (56 commits) io_uring/fdinfo: fix io_uring_show_fdinfo() misuse of ->d_iname io_uring: reuse io_should_terminate_tw() for cmds io_uring: Factor out a function to parse restrictions io_uring/rsrc: require cloned buffers to share accounting contexts io_uring: simplify the SQPOLL thread check when cancelling requests io_uring: expose read/write attribute capability io_uring/rw: don't gate retry on completion context io_uring/rw: handle -EAGAIN retry at IO completion time io_uring/rw: use io_rw_recycle() from cleanup path io_uring/rsrc: simplify the bvec iter count calculation io_uring: ensure io_queue_deferred() is out-of-line io_uring/rw: always clear ->bytes_done on io_async_rw setup io_uring/rw: use NULL for rw->free_iovec assigment io_uring/rw: don't mask in f_iocb_flags io_uring/msg_ring: Drop custom destructor io_uring: Move old async data allocation helper to header io_uring/rw: Allocate async data through helper io_uring/net: Allocate msghdr async data through helper io_uring/uring_cmd: Allocate async data through generic helper io_uring/poll: Allocate apoll with generic alloc_cache helper ...

io_uring/timeout: fix multishot updates

2025-01-04T18:39:00Z

After update only the first shot of a multishot timeout request adheres to the new timeout value while all subsequent retries continue to use the old value. Don't forget to update the timeout stored in struct io_timeout_data. Cc: stable@vger.kernel.org Fixes: ea97f6c8558e8 ("io_uring: add support for multishot timeouts") Reported-by: Christian Mazakas Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/e6516c3304eb654ec234cfa65c88a9579861e597.1736015288.git.asml.silence@gmail.com Signed-off-by: Jens Axboe

io_uring/timeout: flush timeouts outside of the timeout lock

2024-12-30T21:15:17Z

syzbot reports that a recent fix causes nesting issues between the (now) raw timeoutlock and the eventfd locking: ============================= [ BUG: Invalid wait context ] 6.13.0-rc4-00080-g9828a4c0901f #29 Not tainted ----------------------------- kworker/u32:0/68094 is trying to lock: ffff000014d7a520 (&ctx->wqh#2){..-.}-{3:3}, at: eventfd_signal_mask+0x64/0x180 other info that might help us debug this: context-{5:5} 6 locks held by kworker/u32:0/68094: #0: ffff0000c1d98148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x4e8/0xfc0 #1: ffff80008d927c78 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x53c/0xfc0 #2: ffff0000c59bc3d8 (&ctx->completion_lock){+.+.}-{3:3}, at: io_kill_timeouts+0x40/0x180 #3: ffff0000c59bc358 (&ctx->timeout_lock){-.-.}-{2:2}, at: io_kill_timeouts+0x48/0x180 #4: ffff800085127aa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0x8/0x38 #5: ffff800085127aa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0x8/0x38 stack backtrace: CPU: 7 UID: 0 PID: 68094 Comm: kworker/u32:0 Not tainted 6.13.0-rc4-00080-g9828a4c0901f #29 Hardware name: linux,dummy-virt (DT) Workqueue: iou_exit io_ring_exit_work Call trace: show_stack+0x1c/0x30 (C) __dump_stack+0x24/0x30 dump_stack_lvl+0x60/0x80 dump_stack+0x14/0x20 __lock_acquire+0x19f8/0x60c8 lock_acquire+0x1a4/0x540 _raw_spin_lock_irqsave+0x90/0xd0 eventfd_signal_mask+0x64/0x180 io_eventfd_signal+0x64/0x108 io_req_local_work_add+0x294/0x430 __io_req_task_work_add+0x1c0/0x270 io_kill_timeout+0x1f0/0x288 io_kill_timeouts+0xd4/0x180 io_uring_try_cancel_requests+0x2e8/0x388 io_ring_exit_work+0x150/0x550 process_one_work+0x5e8/0xfc0 worker_thread+0x7ec/0xc80 kthread+0x24c/0x300 ret_from_fork+0x10/0x20 because after the preempt-rt fix for the timeout lock nesting inside the io-wq lock, we now have the eventfd spinlock nesting inside the raw timeout spinlock. Rather than play whack-a-mole with other nesting on the timeout lock, split the deletion and killing of timeouts so queueing the task_work for the timeout cancelations can get done outside of the timeout lock. Reported-by: syzbot+b1fc199a40b65d601b65@syzkaller.appspotmail.com Fixes: 020b40f35624 ("io_uring: make ctx->timeout_lock a raw spinlock") Signed-off-by: Jens Axboe

io_uring: Move old async data allocation helper to header

2024-12-27T17:08:11Z

There are two remaining uses of the old async data allocator that do not rely on the alloc cache. I don't want to make them use the new allocator helper because that would require a if(cache) check, which will result in dead code for the cached case (for callers passing a cache, gcc can't prove the cache isn't NULL, and will therefore preserve the check. Since this is an inline function and just a few lines long, keep a second helper to deal with cases where we don't have an async data cache. No functional change intended here. This is just moving the helper around and making it inline. Signed-off-by: Gabriel Krisman Bertazi Link: https://lore.kernel.org/r/20241216204615.759089-9-krisman@suse.de Signed-off-by: Jens Axboe

io_uring: make ctx->timeout_lock a raw spinlock

2024-12-17T15:21:46Z

Chase reports that their tester complaints about a locking context mismatch: ============================= [ BUG: Invalid wait context ] 6.13.0-rc1-gf137f14b7ccb-dirty #9 Not tainted ----------------------------- syz.1.25198/182604 is trying to lock: ffff88805e66a358 (&ctx->timeout_lock){-.-.}-{3:3}, at: spin_lock_irq include/linux/spinlock.h:376 [inline] ffff88805e66a358 (&ctx->timeout_lock){-.-.}-{3:3}, at: io_match_task_safe io_uring/io_uring.c:218 [inline] ffff88805e66a358 (&ctx->timeout_lock){-.-.}-{3:3}, at: io_match_task_safe+0x187/0x250 io_uring/io_uring.c:204 other info that might help us debug this: context-{5:5} 1 lock held by syz.1.25198/182604: #0: ffff88802b7d48c0 (&acct->lock){+.+.}-{2:2}, at: io_acct_cancel_pending_work+0x2d/0x6b0 io_uring/io-wq.c:1049 stack backtrace: CPU: 0 UID: 0 PID: 182604 Comm: syz.1.25198 Not tainted 6.13.0-rc1-gf137f14b7ccb-dirty #9 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x82/0xd0 lib/dump_stack.c:120 print_lock_invalid_wait_context kernel/locking/lockdep.c:4826 [inline] check_wait_context kernel/locking/lockdep.c:4898 [inline] __lock_acquire+0x883/0x3c80 kernel/locking/lockdep.c:5176 lock_acquire.part.0+0x11b/0x370 kernel/locking/lockdep.c:5849 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0x36/0x50 kernel/locking/spinlock.c:170 spin_lock_irq include/linux/spinlock.h:376 [inline] io_match_task_safe io_uring/io_uring.c:218 [inline] io_match_task_safe+0x187/0x250 io_uring/io_uring.c:204 io_acct_cancel_pending_work+0xb8/0x6b0 io_uring/io-wq.c:1052 io_wq_cancel_pending_work io_uring/io-wq.c:1074 [inline] io_wq_cancel_cb+0xb0/0x390 io_uring/io-wq.c:1112 io_uring_try_cancel_requests+0x15e/0xd70 io_uring/io_uring.c:3062 io_uring_cancel_generic+0x6ec/0x8c0 io_uring/io_uring.c:3140 io_uring_files_cancel include/linux/io_uring.h:20 [inline] do_exit+0x494/0x27a0 kernel/exit.c:894 do_group_exit+0xb3/0x250 kernel/exit.c:1087 get_signal+0x1d77/0x1ef0 kernel/signal.c:3017 arch_do_signal_or_restart+0x79/0x5b0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xd8/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f which is because io_uring has ctx->timeout_lock nesting inside the io-wq acct lock, the latter of which is used from inside the scheduler and hence is a raw spinlock, while the former is a "normal" spinlock and can hence be sleeping on PREEMPT_RT. Change ctx->timeout_lock to be a raw spinlock to solve this nesting dependency on PREEMPT_RT=y. Reported-by: chase xd Signed-off-by: Jens Axboe

Merge tag 'timers-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2024-11-20T00:35:06Z

Pull timer updates from Thomas Gleixner: "A rather large update for timekeeping and timers: - The final step to get rid of auto-rearming posix-timers posix-timers are currently auto-rearmed by the kernel when the signal of the timer is ignored so that the timer signal can be delivered once the corresponding signal is unignored. This requires to throttle the timer to prevent a DoS by small intervals and keeps the system pointlessly out of low power states for no value. This is a long standing non-trivial problem due to the lock order of posix-timer lock and the sighand lock along with life time issues as the timer and the sigqueue have different life time rules. Cure this by: - Embedding the sigqueue into the timer struct to have the same life time rules. Aside of that this also avoids the lookup of the timer in the signal delivery and rearm path as it's just a always valid container_of() now. - Queuing ignored timer signals onto a seperate ignored list. - Moving queued timer signals onto the ignored list when the signal is switched to SIG_IGN before it could be delivered. - Walking the ignored list when SIG_IGN is lifted and requeue the signals to the actual signal lists. This allows the signal delivery code to rearm the timer. This also required to consolidate the signal delivery rules so they are consistent across all situations. With that all self test scenarios finally succeed. - Core infrastructure for VFS multigrain timestamping This is required to allow the kernel to use coarse grained time stamps by default and switch to fine grained time stamps when inode attributes are actively observed via getattr(). These changes have been provided to the VFS tree as well, so that the VFS specific infrastructure could be built on top. - Cleanup and consolidation of the sleep() infrastructure - Move all sleep and timeout functions into one file - Rework udelay() and ndelay() into proper documented inline functions and replace the hardcoded magic numbers by proper defines. - Rework the fsleep() implementation to take the reality of the timer wheel granularity on different HZ values into account. Right now the boundaries are hard coded time ranges which fail to provide the requested accuracy on different HZ settings. - Update documentation for all sleep/timeout related functions and fix up stale documentation links all over the place - Fixup a few usage sites - Rework of timekeeping and adjtimex(2) to prepare for multiple PTP clocks A system can have multiple PTP clocks which are participating in seperate and independent PTP clock domains. So far the kernel only considers the PTP clock which is based on CLOCK TAI relevant as that's the clock which drives the timekeeping adjustments via the various user space daemons through adjtimex(2). The non TAI based clock domains are accessible via the file descriptor based posix clocks, but their usability is very limited. They can't be accessed fast as they always go all the way out to the hardware and they cannot be utilized in the kernel itself. As Time Sensitive Networking (TSN) gains traction it is required to provide fast user and kernel space access to these clocks. The approach taken is to utilize the timekeeping and adjtimex(2) infrastructure to provide this access in a similar way how the kernel provides access to clock MONOTONIC, REALTIME etc. Instead of creating a duplicated infrastructure this rework converts timekeeping and adjtimex(2) into generic functionality which operates on pointers to data structures instead of using static variables. This allows to provide time accessors and adjtimex(2) functionality for the independent PTP clocks in a subsequent step. - Consolidate hrtimer initialization hrtimers are set up by initializing the data structure and then seperately setting the callback function for historical reasons. That's an extra unnecessary step and makes Rust support less straight forward than it should be. Provide a new set of hrtimer_setup*() functions and convert the core code and a few usage sites of the less frequently used interfaces over. The bulk of the htimer_init() to hrtimer_setup() conversion is already prepared and scheduled for the next merge window. - Drivers: - Ensure that the global timekeeping clocksource is utilizing the cluster 0 timer on MIPS multi-cluster systems. Otherwise CPUs on different clusters use their cluster specific clocksource which is not guaranteed to be synchronized with other clusters. - Mostly boring cleanups, fixes, improvements and code movement" * tag 'timers-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (140 commits) posix-timers: Fix spurious warning on double enqueue versus do_exit() clocksource/drivers/arm_arch_timer: Use of_property_present() for non-boolean properties clocksource/drivers/gpx: Remove redundant casts clocksource/drivers/timer-ti-dm: Fix child node refcount handling dt-bindings: timer: actions,owl-timer: convert to YAML clocksource/drivers/ralink: Add Ralink System Tick Counter driver clocksource/drivers/mips-gic-timer: Always use cluster 0 counter as clocksource clocksource/drivers/timer-ti-dm: Don't fail probe if int not found clocksource/drivers:sp804: Make user selectable clocksource/drivers/dw_apb: Remove unused dw_apb_clockevent functions hrtimers: Delete hrtimer_init_on_stack() alarmtimer: Switch to use hrtimer_setup() and hrtimer_setup_on_stack() io_uring: Switch to use hrtimer_setup_on_stack() sched/idle: Switch to use hrtimer_setup_on_stack() hrtimers: Delete hrtimer_init_sleeper_on_stack() wait: Switch to use hrtimer_setup_sleeper_on_stack() timers: Switch to use hrtimer_setup_sleeper_on_stack() net: pktgen: Switch to use hrtimer_setup_sleeper_on_stack() futex: Switch to use hrtimer_setup_sleeper_on_stack() fs/aio: Switch to use hrtimer_setup_sleeper_on_stack() ...