diff options
| author | Jens Axboe <axboe@kernel.dk> | 2020-04-03 11:26:26 -0600 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2020-04-03 11:35:57 -0600 |
| commit | aa96bf8a9ee33457b7e3ea43e97dfa1e3a15ab20 (patch) | |
| tree | a3ba2c7171210464132794274827829d17dd15b4 /fs | |
| parent | 3537b6a7c65434d0d2cc0c9862e69be11c367fdc (diff) | |
io_uring: use io-wq manager as backup task if task is exiting
If the original task is (or has) exited, then the task work will not get
queued properly. Allow for using the io-wq manager task to queue this
work for execution, and ensure that the io-wq manager notices and runs
this work if woken up (or exiting).
Reported-by: Dan Melnic <dmm@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/io-wq.c | 12 | ||||
| -rw-r--r-- | fs/io-wq.h | 2 | ||||
| -rw-r--r-- | fs/io_uring.c | 13 |
3 files changed, 23 insertions, 4 deletions
diff --git a/fs/io-wq.c b/fs/io-wq.c index cc5cf2209fb0..4023c9846860 100644 --- a/fs/io-wq.c +++ b/fs/io-wq.c @@ -17,6 +17,7 @@ #include <linux/kthread.h> #include <linux/rculist_nulls.h> #include <linux/fs_struct.h> +#include <linux/task_work.h> #include "io-wq.h" @@ -716,6 +717,9 @@ static int io_wq_manager(void *data) complete(&wq->done); while (!kthread_should_stop()) { + if (current->task_works) + task_work_run(); + for_each_node(node) { struct io_wqe *wqe = wq->wqes[node]; bool fork_worker[2] = { false, false }; @@ -738,6 +742,9 @@ static int io_wq_manager(void *data) schedule_timeout(HZ); } + if (current->task_works) + task_work_run(); + return 0; err: set_bit(IO_WQ_BIT_ERROR, &wq->state); @@ -1124,3 +1131,8 @@ void io_wq_destroy(struct io_wq *wq) if (refcount_dec_and_test(&wq->use_refs)) __io_wq_destroy(wq); } + +struct task_struct *io_wq_get_task(struct io_wq *wq) +{ + return wq->manager; +} diff --git a/fs/io-wq.h b/fs/io-wq.h index 3ee7356d6be5..5ba12de7572f 100644 --- a/fs/io-wq.h +++ b/fs/io-wq.h @@ -136,6 +136,8 @@ typedef bool (work_cancel_fn)(struct io_wq_work *, void *); enum io_wq_cancel io_wq_cancel_cb(struct io_wq *wq, work_cancel_fn *cancel, void *data); +struct task_struct *io_wq_get_task(struct io_wq *wq); + #if defined(CONFIG_IO_WQ) extern void io_wq_worker_sleeping(struct task_struct *); extern void io_wq_worker_running(struct task_struct *); diff --git a/fs/io_uring.c b/fs/io_uring.c index b343525a4d2e..2460c3333f70 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -4120,6 +4120,7 @@ static int __io_async_wake(struct io_kiocb *req, struct io_poll_iocb *poll, __poll_t mask, task_work_func_t func) { struct task_struct *tsk; + int ret; /* for instances that support it check for an event match first: */ if (mask && !(mask & poll->events)) @@ -4133,11 +4134,15 @@ static int __io_async_wake(struct io_kiocb *req, struct io_poll_iocb *poll, req->result = mask; init_task_work(&req->task_work, func); /* - * If this fails, then the task is exiting. If that is the case, then - * the exit check will ultimately cancel these work items. Hence we - * don't need to check here and handle it specifically. + * If this fails, then the task is exiting. Punt to one of the io-wq + * threads to ensure the work gets run, we can't always rely on exit + * cancelation taking care of this. */ - task_work_add(tsk, &req->task_work, true); + ret = task_work_add(tsk, &req->task_work, true); + if (unlikely(ret)) { + tsk = io_wq_get_task(req->ctx->io_wq); + task_work_add(tsk, &req->task_work, true); + } wake_up_process(tsk); return 1; } |