[PATCH for-next 5/7] io_uring: refactor io_put_task helpers

Pavel Begunkov
2023-01-23T14:42:16Z

Add a helper for putting refs from the target task context, rename
__io_put_task() and add a couple of comments around. Use the remote
version for __io_req_complete_post(), the local is only needed for
__io_submit_flush_completions().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
io_uring/io_uring.c | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 8a99791a507a..faada7e76f2d 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -713,7 +713,8 @@ static void io_cqring_overflow_flush(struct io_ring_ctx *ctx)
io_cqring_do_overflow_flush(ctx);
}

-static void __io_put_task(struct task_struct *task, int nr)
+/* can be called by any task */
+static void io_put_task_remote(struct task_struct *task, int nr)
{
struct io_uring_task *tctx = task->io_uring;

@@ -723,13 +724,19 @@ static void __io_put_task(struct task_struct *task, int nr)
put_task_struct_many(task, nr);
}

+/* used by a task to put its own references */
+static void io_put_task_local(struct task_struct *task, int nr)
+{
+ task->io_uring->cached_refs += nr;
+}
+
/* must to be called somewhat shortly after putting a request */
static inline void io_put_task(struct task_struct *task, int nr)
{
if (likely(task == current))
- task->io_uring->cached_refs += nr;
+ io_put_task_local(task, nr);
else
- __io_put_task(task, nr);
+ io_put_task_remote(task, nr);
}

void io_task_refs_refill(struct io_uring_task *tctx)
@@ -982,7 +989,7 @@ static void __io_req_complete_post(struct io_kiocb *req)
* we don't hold ->completion_lock. Clean them here to avoid
* deadlocks.
*/
- io_put_task(req->task, 1);
+ io_put_task_remote(req->task, 1);
wq_list_add_head(&req->comp_list, &ctx->locked_free_list);
ctx->locked_free_nr++;
}
@@ -1105,7 +1112,7 @@ __cold void io_free_req(struct io_kiocb *req)

io_req_put_rsrc(req);
io_dismantle_req(req);
- io_put_task(req->task, 1);
+ io_put_task_remote(req->task, 1);

spin_lock(&ctx->completion_lock);
wq_list_add_head(&req->comp_list, &ctx->locked_free_list);
--
2.38.1