From 0b81e80c813f92520667c872d499a2dba8377be6 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 16 Feb 2021 10:33:53 -0700 Subject: [PATCH] io_uring: tctx->task_lock should be IRQ safe We add task_work from any context, hence we need to ensure that we can tolerate it being from IRQ context as well. Fixes: 7cbf1722d5fc ("io_uring: provide FIFO ordering for task_work") Signed-off-by: Jens Axboe --- fs/io_uring.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index a9d094f..58dd104 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2186,10 +2186,10 @@ static bool __tctx_task_work(struct io_uring_task *tctx) if (wq_list_empty(&tctx->task_list)) return false; - spin_lock(&tctx->task_lock); + spin_lock_irq(&tctx->task_lock); list = tctx->task_list; INIT_WQ_LIST(&tctx->task_list); - spin_unlock(&tctx->task_lock); + spin_unlock_irq(&tctx->task_lock); node = list.first; while (node) { @@ -2236,13 +2236,14 @@ static int io_task_work_add(struct task_struct *tsk, struct io_kiocb *req, { struct io_uring_task *tctx = tsk->io_uring; struct io_wq_work_node *node, *prev; + unsigned long flags; int ret; WARN_ON_ONCE(!tctx); - spin_lock(&tctx->task_lock); + spin_lock_irqsave(&tctx->task_lock, flags); wq_list_add_tail(&req->io_task_work.node, &tctx->task_list); - spin_unlock(&tctx->task_lock); + spin_unlock_irqrestore(&tctx->task_lock, flags); /* task_work already pending, we're done */ if (test_bit(0, &tctx->task_state) || @@ -2257,7 +2258,7 @@ static int io_task_work_add(struct task_struct *tsk, struct io_kiocb *req, * in the list, it got run and we're fine. */ ret = 0; - spin_lock(&tctx->task_lock); + spin_lock_irqsave(&tctx->task_lock, flags); wq_list_for_each(node, prev, &tctx->task_list) { if (&req->io_task_work.node == node) { wq_list_del(&tctx->task_list, node, prev); @@ -2265,7 +2266,7 @@ static int io_task_work_add(struct task_struct *tsk, struct io_kiocb *req, break; } } - spin_unlock(&tctx->task_lock); + spin_unlock_irqrestore(&tctx->task_lock, flags); clear_bit(0, &tctx->task_state); return ret; } -- 2.7.4