leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

io_uring: tctx->task_lock should be IRQ safe

Browse Source 
We add task_work from any context, hence we need to ensure that we can
tolerate it being from IRQ context as well.

Fixes: 7cbf1722d5 ("io_uring: provide FIFO ordering for task_work")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Jens Axboe 2021-02-16 10:33:53 -07:00
parent 0d4370cfe3
commit 0b81e80c81
1 changed files with 7 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
fs/io_uring.c
View File

@ -2186,10 +2186,10 @@ static bool __tctx_task_work(struct io_uring_task *tctx)
if (wq_list_empty(&tctx->task_list)) if (wq_list_empty(&tctx->task_list))
return false; return false;
spin_lock(&tctx->task_lock); spin_lock_irq(&tctx->task_lock);
list = tctx->task_list; list = tctx->task_list;
INIT_WQ_LIST(&tctx->task_list); INIT_WQ_LIST(&tctx->task_list);
spin_unlock(&tctx->task_lock); spin_unlock_irq(&tctx->task_lock);
node = list.first; node = list.first;
while (node) { 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_uring_task *tctx = tsk->io_uring;
struct io_wq_work_node *node, *prev; struct io_wq_work_node *node, *prev;
unsigned long flags;
int ret; int ret;
WARN_ON_ONCE(!tctx); 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); 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 */ /* task_work already pending, we're done */
if (test_bit(0, &tctx->task_state) || 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. * in the list, it got run and we're fine.
*/ */
ret = 0; ret = 0;
spin_lock(&tctx->task_lock); spin_lock_irqsave(&tctx->task_lock, flags);
wq_list_for_each(node, prev, &tctx->task_list) { wq_list_for_each(node, prev, &tctx->task_list) {
if (&req->io_task_work.node == node) { if (&req->io_task_work.node == node) {
wq_list_del(&tctx->task_list, node, prev); 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; break;
} }
} }
spin_unlock(&tctx->task_lock); spin_unlock_irqrestore(&tctx->task_lock, flags);
clear_bit(0, &tctx->task_state); clear_bit(0, &tctx->task_state);
return ret; return ret;
} }