diff options
Diffstat (limited to 'io_uring/io_uring.c')
| -rw-r--r-- | io_uring/io_uring.c | 467 |
1 files changed, 6 insertions, 461 deletions
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 3fc59a22d54e..17c555aa03bc 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -92,6 +92,7 @@ #include "io_uring_types.h" #include "io_uring.h" #include "refs.h" +#include "sqpoll.h" #include "xattr.h" #include "nop.h" @@ -109,7 +110,6 @@ #define IORING_MAX_ENTRIES 32768 #define IORING_MAX_CQ_ENTRIES (2 * IORING_MAX_ENTRIES) -#define IORING_SQPOLL_CAP_ENTRIES_VALUE 8 /* only define max */ #define IORING_MAX_FIXED_FILES (1U << 20) @@ -214,31 +214,6 @@ struct io_buffer { __u16 bgid; }; -enum { - IO_SQ_THREAD_SHOULD_STOP = 0, - IO_SQ_THREAD_SHOULD_PARK, -}; - -struct io_sq_data { - refcount_t refs; - atomic_t park_pending; - struct mutex lock; - - /* ctx's that are using this sqd */ - struct list_head ctx_list; - - struct task_struct *thread; - struct wait_queue_head wait; - - unsigned sq_thread_idle; - int sq_cpu; - pid_t task_pid; - pid_t task_tgid; - - unsigned long state; - struct completion exited; -}; - #define IO_COMPL_BATCH 32 #define IO_REQ_CACHE_SIZE 32 #define IO_REQ_ALLOC_BATCH 8 @@ -402,7 +377,6 @@ static void io_uring_del_tctx_node(unsigned long index); static void io_uring_try_cancel_requests(struct io_ring_ctx *ctx, struct task_struct *task, bool cancel_all); -static void io_uring_cancel_generic(bool cancel_all, struct io_sq_data *sqd); static void io_dismantle_req(struct io_kiocb *req); static int __io_register_rsrc_update(struct io_ring_ctx *ctx, unsigned type, @@ -1079,13 +1053,6 @@ static void __io_commit_cqring_flush(struct io_ring_ctx *ctx) io_eventfd_signal(ctx); } -static inline bool io_sqring_full(struct io_ring_ctx *ctx) -{ - struct io_rings *r = ctx->rings; - - return READ_ONCE(r->sq.tail) - ctx->cached_sq_head == ctx->sq_entries; -} - static inline unsigned int __io_cqring_events(struct io_ring_ctx *ctx) { return ctx->cached_cq_tail - READ_ONCE(ctx->rings->cq.head); @@ -1974,28 +1941,7 @@ static unsigned io_cqring_events(struct io_ring_ctx *ctx) return __io_cqring_events(ctx); } -static inline unsigned int io_sqring_entries(struct io_ring_ctx *ctx) -{ - struct io_rings *rings = ctx->rings; - - /* make sure SQ entry isn't read before tail */ - return smp_load_acquire(&rings->sq.tail) - ctx->cached_sq_head; -} - -static inline bool io_run_task_work(void) -{ - if (test_thread_flag(TIF_NOTIFY_SIGNAL) || task_work_pending(current)) { - __set_current_state(TASK_RUNNING); - clear_notify_signal(); - if (task_work_pending(current)) - task_work_run(); - return true; - } - - return false; -} - -static int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin) +int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin) { struct io_wq_work_node *pos, *start, *prev; unsigned int poll_flags = BLK_POLL_NOSLEEP; @@ -5297,7 +5243,7 @@ static const struct io_uring_sqe *io_get_sqe(struct io_ring_ctx *ctx) return NULL; } -static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr) +int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr) __must_hold(&ctx->uring_lock) { unsigned int entries = io_sqring_entries(ctx); @@ -5349,173 +5295,6 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr) return ret; } -static inline bool io_sqd_events_pending(struct io_sq_data *sqd) -{ - return READ_ONCE(sqd->state); -} - -static int __io_sq_thread(struct io_ring_ctx *ctx, bool cap_entries) -{ - unsigned int to_submit; - int ret = 0; - - to_submit = io_sqring_entries(ctx); - /* if we're handling multiple rings, cap submit size for fairness */ - if (cap_entries && to_submit > IORING_SQPOLL_CAP_ENTRIES_VALUE) - to_submit = IORING_SQPOLL_CAP_ENTRIES_VALUE; - - if (!wq_list_empty(&ctx->iopoll_list) || to_submit) { - const struct cred *creds = NULL; - - if (ctx->sq_creds != current_cred()) - creds = override_creds(ctx->sq_creds); - - mutex_lock(&ctx->uring_lock); - if (!wq_list_empty(&ctx->iopoll_list)) - io_do_iopoll(ctx, true); - - /* - * Don't submit if refs are dying, good for io_uring_register(), - * but also it is relied upon by io_ring_exit_work() - */ - if (to_submit && likely(!percpu_ref_is_dying(&ctx->refs)) && - !(ctx->flags & IORING_SETUP_R_DISABLED)) - ret = io_submit_sqes(ctx, to_submit); - mutex_unlock(&ctx->uring_lock); - - if (to_submit && wq_has_sleeper(&ctx->sqo_sq_wait)) - wake_up(&ctx->sqo_sq_wait); - if (creds) - revert_creds(creds); - } - - return ret; -} - -static __cold void io_sqd_update_thread_idle(struct io_sq_data *sqd) -{ - struct io_ring_ctx *ctx; - unsigned sq_thread_idle = 0; - - list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) - sq_thread_idle = max(sq_thread_idle, ctx->sq_thread_idle); - sqd->sq_thread_idle = sq_thread_idle; -} - -static bool io_sqd_handle_event(struct io_sq_data *sqd) -{ - bool did_sig = false; - struct ksignal ksig; - - if (test_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state) || - signal_pending(current)) { - mutex_unlock(&sqd->lock); - if (signal_pending(current)) - did_sig = get_signal(&ksig); - cond_resched(); - mutex_lock(&sqd->lock); - } - return did_sig || test_bit(IO_SQ_THREAD_SHOULD_STOP, &sqd->state); -} - -static int io_sq_thread(void *data) -{ - struct io_sq_data *sqd = data; - struct io_ring_ctx *ctx; - unsigned long timeout = 0; - char buf[TASK_COMM_LEN]; - DEFINE_WAIT(wait); - - snprintf(buf, sizeof(buf), "iou-sqp-%d", sqd->task_pid); - set_task_comm(current, buf); - - if (sqd->sq_cpu != -1) - set_cpus_allowed_ptr(current, cpumask_of(sqd->sq_cpu)); - else - set_cpus_allowed_ptr(current, cpu_online_mask); - current->flags |= PF_NO_SETAFFINITY; - - audit_alloc_kernel(current); - - mutex_lock(&sqd->lock); - while (1) { - bool cap_entries, sqt_spin = false; - - if (io_sqd_events_pending(sqd) || signal_pending(current)) { - if (io_sqd_handle_event(sqd)) - break; - timeout = jiffies + sqd->sq_thread_idle; - } - - cap_entries = !list_is_singular(&sqd->ctx_list); - list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) { - int ret = __io_sq_thread(ctx, cap_entries); - - if (!sqt_spin && (ret > 0 || !wq_list_empty(&ctx->iopoll_list))) - sqt_spin = true; - } - if (io_run_task_work()) - sqt_spin = true; - - if (sqt_spin || !time_after(jiffies, timeout)) { - cond_resched(); - if (sqt_spin) - timeout = jiffies + sqd->sq_thread_idle; - continue; - } - - prepare_to_wait(&sqd->wait, &wait, TASK_INTERRUPTIBLE); - if (!io_sqd_events_pending(sqd) && !task_work_pending(current)) { - bool needs_sched = true; - - list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) { - atomic_or(IORING_SQ_NEED_WAKEUP, - &ctx->rings->sq_flags); - if ((ctx->flags & IORING_SETUP_IOPOLL) && - !wq_list_empty(&ctx->iopoll_list)) { - needs_sched = false; - break; - } - - /* - * Ensure the store of the wakeup flag is not - * reordered with the load of the SQ tail - */ - smp_mb__after_atomic(); - - if (io_sqring_entries(ctx)) { - needs_sched = false; - break; - } - } - - if (needs_sched) { - mutex_unlock(&sqd->lock); - schedule(); - mutex_lock(&sqd->lock); - } - list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) - atomic_andnot(IORING_SQ_NEED_WAKEUP, - &ctx->rings->sq_flags); - } - - finish_wait(&sqd->wait, &wait); - timeout = jiffies + sqd->sq_thread_idle; - } - - io_uring_cancel_generic(true, sqd); - sqd->thread = NULL; - list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) - atomic_or(IORING_SQ_NEED_WAKEUP, &ctx->rings->sq_flags); - io_run_task_work(); - mutex_unlock(&sqd->lock); - - audit_free(current); - - complete(&sqd->exited); - do_exit(0); -} - struct io_wait_queue { struct wait_queue_entry wq; struct io_ring_ctx *ctx; @@ -5934,131 +5713,6 @@ static int io_sqe_files_unregister(struct io_ring_ctx *ctx) return ret; } -static void io_sq_thread_unpark(struct io_sq_data *sqd) - __releases(&sqd->lock) -{ - WARN_ON_ONCE(sqd->thread == current); - - /* - * Do the dance but not conditional clear_bit() because it'd race with - * other threads incrementing park_pending and setting the bit. - */ - clear_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state); - if (atomic_dec_return(&sqd->park_pending)) - set_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state); - mutex_unlock(&sqd->lock); -} - -static void io_sq_thread_park(struct io_sq_data *sqd) - __acquires(&sqd->lock) -{ - WARN_ON_ONCE(sqd->thread == current); - - atomic_inc(&sqd->park_pending); - set_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state); - mutex_lock(&sqd->lock); - if (sqd->thread) - wake_up_process(sqd->thread); -} - -static void io_sq_thread_stop(struct io_sq_data *sqd) -{ - WARN_ON_ONCE(sqd->thread == current); - WARN_ON_ONCE(test_bit(IO_SQ_THREAD_SHOULD_STOP, &sqd->state)); - - set_bit(IO_SQ_THREAD_SHOULD_STOP, &sqd->state); - mutex_lock(&sqd->lock); - if (sqd->thread) - wake_up_process(sqd->thread); - mutex_unlock(&sqd->lock); - wait_for_completion(&sqd->exited); -} - -static void io_put_sq_data(struct io_sq_data *sqd) -{ - if (refcount_dec_and_test(&sqd->refs)) { - WARN_ON_ONCE(atomic_read(&sqd->park_pending)); - - io_sq_thread_stop(sqd); - kfree(sqd); - } -} - -static void io_sq_thread_finish(struct io_ring_ctx *ctx) -{ - struct io_sq_data *sqd = ctx->sq_data; - - if (sqd) { - io_sq_thread_park(sqd); - list_del_init(&ctx->sqd_list); - io_sqd_update_thread_idle(sqd); - io_sq_thread_unpark(sqd); - - io_put_sq_data(sqd); - ctx->sq_data = NULL; - } -} - -static struct io_sq_data *io_attach_sq_data(struct io_uring_params *p) -{ - struct io_ring_ctx *ctx_attach; - struct io_sq_data *sqd; - struct fd f; - - f = fdget(p->wq_fd); - if (!f.file) - return ERR_PTR(-ENXIO); - if (f.file->f_op != &io_uring_fops) { - fdput(f); - return ERR_PTR(-EINVAL); - } - - ctx_attach = f.file->private_data; - sqd = ctx_attach->sq_data; - if (!sqd) { - fdput(f); - return ERR_PTR(-EINVAL); - } - if (sqd->task_tgid != current->tgid) { - fdput(f); - return ERR_PTR(-EPERM); - } - - refcount_inc(&sqd->refs); - fdput(f); - return sqd; -} - -static struct io_sq_data *io_get_sq_data(struct io_uring_params *p, - bool *attached) -{ - struct io_sq_data *sqd; - - *attached = false; - if (p->flags & IORING_SETUP_ATTACH_WQ) { - sqd = io_attach_sq_data(p); - if (!IS_ERR(sqd)) { - *attached = true; - return sqd; - } - /* fall through for EPERM case, setup new sqd/task */ - if (PTR_ERR(sqd) != -EPERM) - return sqd; - } - - sqd = kzalloc(sizeof(*sqd), GFP_KERNEL); - if (!sqd) - return ERR_PTR(-ENOMEM); - - atomic_set(&sqd->park_pending, 0); - refcount_set(&sqd->refs, 1); - INIT_LIST_HEAD(&sqd->ctx_list); - mutex_init(&sqd->lock); - init_waitqueue_head(&sqd->wait); - init_completion(&sqd->exited); - return sqd; -} - /* * Ensure the UNIX gc is aware of our file set, so we are certain that * the io_uring can be safely unregistered on process exit, even if we have @@ -6495,8 +6149,8 @@ static struct io_wq *io_init_wq_offload(struct io_ring_ctx *ctx, return io_wq_create(concurrency, &data); } -static __cold int io_uring_alloc_task_context(struct task_struct *task, - struct io_ring_ctx *ctx) +__cold int io_uring_alloc_task_context(struct task_struct *task, + struct io_ring_ctx *ctx) { struct io_uring_task *tctx; int ret; @@ -6554,96 +6208,6 @@ void __io_uring_free(struct task_struct *tsk) tsk->io_uring = NULL; } -static __cold int io_sq_offload_create(struct io_ring_ctx *ctx, - struct io_uring_params *p) -{ - int ret; - - /* Retain compatibility with failing for an invalid attach attempt */ - if ((ctx->flags & (IORING_SETUP_ATTACH_WQ | IORING_SETUP_SQPOLL)) == - IORING_SETUP_ATTACH_WQ) { - struct fd f; - - f = fdget(p->wq_fd); - if (!f.file) - return -ENXIO; - if (f.file->f_op != &io_uring_fops) { - fdput(f); - return -EINVAL; - } - fdput(f); - } - if (ctx->flags & IORING_SETUP_SQPOLL) { - struct task_struct *tsk; - struct io_sq_data *sqd; - bool attached; - - ret = security_uring_sqpoll(); - if (ret) - return ret; - - sqd = io_get_sq_data(p, &attached); - if (IS_ERR(sqd)) { - ret = PTR_ERR(sqd); - goto err; - } - - ctx->sq_creds = get_current_cred(); - ctx->sq_data = sqd; - ctx->sq_thread_idle = msecs_to_jiffies(p->sq_thread_idle); - if (!ctx->sq_thread_idle) - ctx->sq_thread_idle = HZ; - - io_sq_thread_park(sqd); - list_add(&ctx->sqd_list, &sqd->ctx_list); - io_sqd_update_thread_idle(sqd); - /* don't attach to a dying SQPOLL thread, would be racy */ - ret = (attached && !sqd->thread) ? -ENXIO : 0; - io_sq_thread_unpark(sqd); - - if (ret < 0) - goto err; - if (attached) - return 0; - - if (p->flags & IORING_SETUP_SQ_AFF) { - int cpu = p->sq_thread_cpu; - - ret = -EINVAL; - if (cpu >= nr_cpu_ids || !cpu_online(cpu)) - goto err_sqpoll; - sqd->sq_cpu = cpu; - } else { - sqd->sq_cpu = -1; - } - - sqd->task_pid = current->pid; - sqd->task_tgid = current->tgid; - tsk = create_io_thread(io_sq_thread, sqd, NUMA_NO_NODE); - if (IS_ERR(tsk)) { - ret = PTR_ERR(tsk); - goto err_sqpoll; - } - - sqd->thread = tsk; - ret = io_uring_alloc_task_context(tsk, ctx); - wake_up_new_task(tsk); - if (ret) - goto err; - } else if (p->flags & IORING_SETUP_SQ_AFF) { - /* Can't have SQ_AFF without SQPOLL */ - ret = -EINVAL; - goto err; - } - - return 0; -err_sqpoll: - complete(&ctx->sq_data->exited); -err: - io_sq_thread_finish(ctx); - return ret; -} - static inline void __io_unaccount_mem(struct user_struct *user, unsigned long nr_pages) { @@ -7755,8 +7319,7 @@ static s64 tctx_inflight(struct io_uring_task *tctx, bool tracked) * Find any io_uring ctx that this task has registered or done IO on, and cancel * requests. @sqd should be not-null IFF it's an SQPOLL thread cancellation. */ -static __cold void io_uring_cancel_generic(bool cancel_all, - struct io_sq_data *sqd) +__cold void io_uring_cancel_generic(bool cancel_all, struct io_sq_data *sqd) { struct io_uring_task *tctx = current->io_uring; struct io_ring_ctx *ctx; @@ -8034,24 +7597,6 @@ static unsigned long io_uring_nommu_get_unmapped_area(struct file *file, #endif /* !CONFIG_MMU */ -static int io_sqpoll_wait_sq(struct io_ring_ctx *ctx) -{ - DEFINE_WAIT(wait); - - do { - if (!io_sqring_full(ctx)) - break; - prepare_to_wait(&ctx->sqo_sq_wait, &wait, TASK_INTERRUPTIBLE); - - if (!io_sqring_full(ctx)) - break; - schedule(); - } while (!signal_pending(current)); - - finish_wait(&ctx->sqo_sq_wait, &wait); - return 0; -} - static int io_validate_ext_arg(unsigned flags, const void __user *argp, size_t argsz) { if (flags & IORING_ENTER_EXT_ARG) { |