From c9f06aa7de153cdbe424e7e38be39f2272cf78bc Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 25 May 2022 11:01:04 -0600 Subject: io_uring: move io_uring_task (tctx) helpers into its own file Signed-off-by: Jens Axboe --- io_uring/tctx.c | 332 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 332 insertions(+) create mode 100644 io_uring/tctx.c (limited to 'io_uring/tctx.c') diff --git a/io_uring/tctx.c b/io_uring/tctx.c new file mode 100644 index 000000000000..3f7e9feb6ca2 --- /dev/null +++ b/io_uring/tctx.c @@ -0,0 +1,332 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include +#include +#include + +#include + +#include "io_uring_types.h" +#include "io_uring.h" +#include "tctx.h" + +static struct io_wq *io_init_wq_offload(struct io_ring_ctx *ctx, + struct task_struct *task) +{ + struct io_wq_hash *hash; + struct io_wq_data data; + unsigned int concurrency; + + mutex_lock(&ctx->uring_lock); + hash = ctx->hash_map; + if (!hash) { + hash = kzalloc(sizeof(*hash), GFP_KERNEL); + if (!hash) { + mutex_unlock(&ctx->uring_lock); + return ERR_PTR(-ENOMEM); + } + refcount_set(&hash->refs, 1); + init_waitqueue_head(&hash->wait); + ctx->hash_map = hash; + } + mutex_unlock(&ctx->uring_lock); + + data.hash = hash; + data.task = task; + data.free_work = io_wq_free_work; + data.do_work = io_wq_submit_work; + + /* Do QD, or 4 * CPUS, whatever is smallest */ + concurrency = min(ctx->sq_entries, 4 * num_online_cpus()); + + return io_wq_create(concurrency, &data); +} + +void __io_uring_free(struct task_struct *tsk) +{ + struct io_uring_task *tctx = tsk->io_uring; + + WARN_ON_ONCE(!xa_empty(&tctx->xa)); + WARN_ON_ONCE(tctx->io_wq); + WARN_ON_ONCE(tctx->cached_refs); + + kfree(tctx->registered_rings); + percpu_counter_destroy(&tctx->inflight); + kfree(tctx); + tsk->io_uring = NULL; +} + +__cold int io_uring_alloc_task_context(struct task_struct *task, + struct io_ring_ctx *ctx) +{ + struct io_uring_task *tctx; + int ret; + + tctx = kzalloc(sizeof(*tctx), GFP_KERNEL); + if (unlikely(!tctx)) + return -ENOMEM; + + tctx->registered_rings = kcalloc(IO_RINGFD_REG_MAX, + sizeof(struct file *), GFP_KERNEL); + if (unlikely(!tctx->registered_rings)) { + kfree(tctx); + return -ENOMEM; + } + + ret = percpu_counter_init(&tctx->inflight, 0, GFP_KERNEL); + if (unlikely(ret)) { + kfree(tctx->registered_rings); + kfree(tctx); + return ret; + } + + tctx->io_wq = io_init_wq_offload(ctx, task); + if (IS_ERR(tctx->io_wq)) { + ret = PTR_ERR(tctx->io_wq); + percpu_counter_destroy(&tctx->inflight); + kfree(tctx->registered_rings); + kfree(tctx); + return ret; + } + + xa_init(&tctx->xa); + init_waitqueue_head(&tctx->wait); + atomic_set(&tctx->in_idle, 0); + atomic_set(&tctx->inflight_tracked, 0); + task->io_uring = tctx; + spin_lock_init(&tctx->task_lock); + INIT_WQ_LIST(&tctx->task_list); + INIT_WQ_LIST(&tctx->prio_task_list); + init_task_work(&tctx->task_work, tctx_task_work); + return 0; +} + +int __io_uring_add_tctx_node(struct io_ring_ctx *ctx) +{ + struct io_uring_task *tctx = current->io_uring; + struct io_tctx_node *node; + int ret; + + if (unlikely(!tctx)) { + ret = io_uring_alloc_task_context(current, ctx); + if (unlikely(ret)) + return ret; + + tctx = current->io_uring; + if (ctx->iowq_limits_set) { + unsigned int limits[2] = { ctx->iowq_limits[0], + ctx->iowq_limits[1], }; + + ret = io_wq_max_workers(tctx->io_wq, limits); + if (ret) + return ret; + } + } + if (!xa_load(&tctx->xa, (unsigned long)ctx)) { + node = kmalloc(sizeof(*node), GFP_KERNEL); + if (!node) + return -ENOMEM; + node->ctx = ctx; + node->task = current; + + ret = xa_err(xa_store(&tctx->xa, (unsigned long)ctx, + node, GFP_KERNEL)); + if (ret) { + kfree(node); + return ret; + } + + mutex_lock(&ctx->uring_lock); + list_add(&node->ctx_node, &ctx->tctx_list); + mutex_unlock(&ctx->uring_lock); + } + tctx->last = ctx; + return 0; +} + +/* + * Remove this io_uring_file -> task mapping. + */ +__cold void io_uring_del_tctx_node(unsigned long index) +{ + struct io_uring_task *tctx = current->io_uring; + struct io_tctx_node *node; + + if (!tctx) + return; + node = xa_erase(&tctx->xa, index); + if (!node) + return; + + WARN_ON_ONCE(current != node->task); + WARN_ON_ONCE(list_empty(&node->ctx_node)); + + mutex_lock(&node->ctx->uring_lock); + list_del(&node->ctx_node); + mutex_unlock(&node->ctx->uring_lock); + + if (tctx->last == node->ctx) + tctx->last = NULL; + kfree(node); +} + +__cold void io_uring_clean_tctx(struct io_uring_task *tctx) +{ + struct io_wq *wq = tctx->io_wq; + struct io_tctx_node *node; + unsigned long index; + + xa_for_each(&tctx->xa, index, node) { + io_uring_del_tctx_node(index); + cond_resched(); + } + if (wq) { + /* + * Must be after io_uring_del_tctx_node() (removes nodes under + * uring_lock) to avoid race with io_uring_try_cancel_iowq(). + */ + io_wq_put_and_exit(wq); + tctx->io_wq = NULL; + } +} + +void io_uring_unreg_ringfd(void) +{ + struct io_uring_task *tctx = current->io_uring; + int i; + + for (i = 0; i < IO_RINGFD_REG_MAX; i++) { + if (tctx->registered_rings[i]) { + fput(tctx->registered_rings[i]); + tctx->registered_rings[i] = NULL; + } + } +} + +static int io_ring_add_registered_fd(struct io_uring_task *tctx, int fd, + int start, int end) +{ + struct file *file; + int offset; + + for (offset = start; offset < end; offset++) { + offset = array_index_nospec(offset, IO_RINGFD_REG_MAX); + if (tctx->registered_rings[offset]) + continue; + + file = fget(fd); + if (!file) { + return -EBADF; + } else if (!io_is_uring_fops(file)) { + fput(file); + return -EOPNOTSUPP; + } + tctx->registered_rings[offset] = file; + return offset; + } + + return -EBUSY; +} + +/* + * Register a ring fd to avoid fdget/fdput for each io_uring_enter() + * invocation. User passes in an array of struct io_uring_rsrc_update + * with ->data set to the ring_fd, and ->offset given for the desired + * index. If no index is desired, application may set ->offset == -1U + * and we'll find an available index. Returns number of entries + * successfully processed, or < 0 on error if none were processed. + */ +int io_ringfd_register(struct io_ring_ctx *ctx, void __user *__arg, + unsigned nr_args) +{ + struct io_uring_rsrc_update __user *arg = __arg; + struct io_uring_rsrc_update reg; + struct io_uring_task *tctx; + int ret, i; + + if (!nr_args || nr_args > IO_RINGFD_REG_MAX) + return -EINVAL; + + mutex_unlock(&ctx->uring_lock); + ret = io_uring_add_tctx_node(ctx); + mutex_lock(&ctx->uring_lock); + if (ret) + return ret; + + tctx = current->io_uring; + for (i = 0; i < nr_args; i++) { + int start, end; + + if (copy_from_user(®, &arg[i], sizeof(reg))) { + ret = -EFAULT; + break; + } + + if (reg.resv) { + ret = -EINVAL; + break; + } + + if (reg.offset == -1U) { + start = 0; + end = IO_RINGFD_REG_MAX; + } else { + if (reg.offset >= IO_RINGFD_REG_MAX) { + ret = -EINVAL; + break; + } + start = reg.offset; + end = start + 1; + } + + ret = io_ring_add_registered_fd(tctx, reg.data, start, end); + if (ret < 0) + break; + + reg.offset = ret; + if (copy_to_user(&arg[i], ®, sizeof(reg))) { + fput(tctx->registered_rings[reg.offset]); + tctx->registered_rings[reg.offset] = NULL; + ret = -EFAULT; + break; + } + } + + return i ? i : ret; +} + +int io_ringfd_unregister(struct io_ring_ctx *ctx, void __user *__arg, + unsigned nr_args) +{ + struct io_uring_rsrc_update __user *arg = __arg; + struct io_uring_task *tctx = current->io_uring; + struct io_uring_rsrc_update reg; + int ret = 0, i; + + if (!nr_args || nr_args > IO_RINGFD_REG_MAX) + return -EINVAL; + if (!tctx) + return 0; + + for (i = 0; i < nr_args; i++) { + if (copy_from_user(®, &arg[i], sizeof(reg))) { + ret = -EFAULT; + break; + } + if (reg.resv || reg.data || reg.offset >= IO_RINGFD_REG_MAX) { + ret = -EINVAL; + break; + } + + reg.offset = array_index_nospec(reg.offset, IO_RINGFD_REG_MAX); + if (tctx->registered_rings[reg.offset]) { + fput(tctx->registered_rings[reg.offset]); + tctx->registered_rings[reg.offset] = NULL; + } + } + + return i ? i : ret; +} -- cgit v1.2.3