From baf186c4d345f5a105e63df01100936ad622f369 Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Sat, 6 Mar 2021 11:02:15 +0000 Subject: [PATCH] io_uring: index io_uring->xa by ctx not file We don't use task file notes anymore, and no need left in indexing task->io_uring->xa by file, and replace it with ctx. It's better design-wise, especially since we keep a dangling file, and so have to keep an eye on not dereferencing it. Signed-off-by: Pavel Begunkov Signed-off-by: Jens Axboe --- fs/io_uring.c | 24 +++++++++++------------- include/linux/io_uring.h | 2 +- 2 files changed, 12 insertions(+), 14 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index f448213..01a7fa4 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -809,7 +809,6 @@ struct io_kiocb { struct io_tctx_node { struct list_head ctx_node; struct task_struct *task; - struct file *file; struct io_ring_ctx *ctx; }; @@ -8540,7 +8539,7 @@ static bool io_run_ctx_fallback(struct io_ring_ctx *ctx) struct io_tctx_exit { struct callback_head task_work; struct completion completion; - unsigned long index; + struct io_ring_ctx *ctx; }; static void io_tctx_exit_cb(struct callback_head *cb) @@ -8554,7 +8553,7 @@ static void io_tctx_exit_cb(struct callback_head *cb) * node. It'll be removed by the end of cancellation, just ignore it. */ if (!atomic_read(&tctx->in_idle)) - io_uring_del_task_file(work->index); + io_uring_del_task_file((unsigned long)work->ctx); complete(&work->completion); } @@ -8579,7 +8578,7 @@ static void io_ring_exit_work(struct work_struct *work) while (!list_empty(&ctx->tctx_list)) { node = list_first_entry(&ctx->tctx_list, struct io_tctx_node, ctx_node); - exit.index = (unsigned long)node->file; + exit.ctx = ctx; init_completion(&exit.completion); init_task_work(&exit.task_work, io_tctx_exit_cb); ret = task_work_add(node->task, &exit.task_work, TWA_SIGNAL); @@ -8798,7 +8797,7 @@ static void io_uring_cancel_task_requests(struct io_ring_ctx *ctx, /* * Note that this task has used io_uring. We use it for cancelation purposes. */ -static int io_uring_add_task_file(struct io_ring_ctx *ctx, struct file *file) +static int io_uring_add_task_file(struct io_ring_ctx *ctx) { struct io_uring_task *tctx = current->io_uring; struct io_tctx_node *node; @@ -8810,18 +8809,17 @@ static int io_uring_add_task_file(struct io_ring_ctx *ctx, struct file *file) return ret; tctx = current->io_uring; } - if (tctx->last != file) { - void *old = xa_load(&tctx->xa, (unsigned long)file); + if (tctx->last != ctx) { + void *old = xa_load(&tctx->xa, (unsigned long)ctx); if (!old) { node = kmalloc(sizeof(*node), GFP_KERNEL); if (!node) return -ENOMEM; node->ctx = ctx; - node->file = file; node->task = current; - ret = xa_err(xa_store(&tctx->xa, (unsigned long)file, + ret = xa_err(xa_store(&tctx->xa, (unsigned long)ctx, node, GFP_KERNEL)); if (ret) { kfree(node); @@ -8832,7 +8830,7 @@ static int io_uring_add_task_file(struct io_ring_ctx *ctx, struct file *file) list_add(&node->ctx_node, &ctx->tctx_list); mutex_unlock(&ctx->uring_lock); } - tctx->last = file; + tctx->last = ctx; } /* @@ -8867,7 +8865,7 @@ static void io_uring_del_task_file(unsigned long index) list_del(&node->ctx_node); mutex_unlock(&node->ctx->uring_lock); - if (tctx->last == node->file) + if (tctx->last == node->ctx) tctx->last = NULL; kfree(node); } @@ -9166,7 +9164,7 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, } submitted = to_submit; } else if (to_submit) { - ret = io_uring_add_task_file(ctx, f.file); + ret = io_uring_add_task_file(ctx); if (unlikely(ret)) goto out; mutex_lock(&ctx->uring_lock); @@ -9375,7 +9373,7 @@ static int io_uring_install_fd(struct io_ring_ctx *ctx, struct file *file) if (fd < 0) return fd; - ret = io_uring_add_task_file(ctx, file); + ret = io_uring_add_task_file(ctx); if (ret) { put_unused_fd(fd); return ret; diff --git a/include/linux/io_uring.h b/include/linux/io_uring.h index 7cb7bd0..9761a0e 100644 --- a/include/linux/io_uring.h +++ b/include/linux/io_uring.h @@ -18,7 +18,7 @@ struct io_uring_task { /* submission side */ struct xarray xa; struct wait_queue_head wait; - struct file *last; + void *last; void *io_wq; struct percpu_counter inflight; atomic_t in_idle; -- 2.7.4